Xylo-oligosaccharides (XOS): A Multifunctional Prebiotic for Gut, Immune, and Metabolic Health in Companion Animals
- XOS resists digestion in the upper gut, reaching the colon where it selectively feeds beneficial bacteria like Bifidobacterium and Lactobacillus.
- Studies in cats and other animals show XOS increases beneficial gut bacteria diversity and short-chain fatty acid (SCFA) production.
- Research links XOS to improved immune response, including stronger antibody response to vaccines in kittens.
- XOS has shown antioxidant, anti-inflammatory, and metabolic benefits, including improved insulin sensitivity and reduced fat accumulation in animal studies.
- Venttura's cold-pressed dog food incorporates XOS as a functional prebiotic ingredient.
I . Introduction
A prebiotic is defined as “a non-digestible dietary component that positively affects the host by selectively stimulating the growth and/or activity of specific beneficial bacteria in the colon, thereby enhancing host health”[1]. In 2004, the definition of prebiotics was refined to include four essential criteria: (1) resistance to breakdown by mammalian digestive enzymes, gastric acid, and gastrointestinal absorption; (2) selective fermentation by gut microbiota (GM); (3) the ability to produce beneficial luminal or systemic effects on host health; and (4) selective promotion of the growth and activity of health-associated GM [2]. According to the consensus panel of the International Scientific Association for Probiotics and Prebiotics, a prebiotic is currently defined as “a substrate that is selectively utilized by host microorganisms, resulting in a health benefit” [5]. Frequently utilized prebiotics in dog food typically consist of simple and complex carbohydrates that supply essential dietary fibers. These commonly include ingredients like lactulose, tagatose, inulin, polydextrose, and various oligosaccharides such as mannanoligosaccharides (MOS), fructo-oligosaccharides (FOS), galacto-oligosaccharides, and xylo-oligosaccharides [6].
Xylooligosaccharides (XOS) are non-digestible oligosaccharides primarily made up of xylose units. Owing to their physicochemical properties, XOS are highly resistant to gastric acids and gastrointestinal digestive enzymes, enabling them to remain undigested in the upper gastrointestinal tract and reach the lower intestine, where they are utilized by beneficial probiotic bacteria, particularly species belonging to the Bifidobacterium and Lactobacillus genera [7]. Xylooligosaccharides (XOS) represent a rising class of prebiotics manufactured by breaking down lignocellulosic materials (LCMs) through either chemical reactions, enzymatic treatments, or a combination of both [8]. The raw biomass of these materials is a complex structure made up of three main components : cellulose, hemicellulose, and lignin, though their exact ratios depend entirely on the specific source material. Typically, cellulose makes up the largest portion at 29.5% to 50.5%, followed by hemicellulose at 19.5% to 40.5%, and lignin accounting for the remaining 15.5% to 24.5% [10]. For XOS production, the critical element is xylan, a specific carbohydrate that constitutes the vast majority of the hemicellulose fraction, roughly 60% to 89% of its total dry weight [11]. Within the commercial prebiotic sector, XOS generally commands a higher price point than alternative options such as fructooligosaccharides, galactooligosaccharides, iso-oligosaccharides, and inulin. The elevated cost is mainly driven by the manufacturing constraints associated with extracting xylan from lignocellulosic biomass, coupled with the high financial expense of the xylanase enzymes needed to break it down [12].
To fulfill the increasing demand for XOS, the use of cost-effective lignocellulosic biomass (LCB) sources such as sugarcane bagasse (SB), crop residues, and corncobs has been proposed as an effective strategy for accelerating industrial-scale production. This approach can support faster commercialization of XOS while also helping to meet its growing market demand [13]. Xylooligosaccharides (XOS) occur naturally within various dietary sources, including honey, milk, bamboo shoots, fruits, and vegetables [3]. Highly regarded as functional oligosaccharides, XOS possess immense potential as prebiotics. These compounds are manufactured as breakdown products through the physical, chemical, or enzymatic processing of xylan, which is sourced from agricultural biomass residues like corncobs, rice straw, and sugarcane residues [14]. XOS consist of xylose monomers connected through β-1,4-xylosidic linkages, and their structure may include branching due to the attachment of various side groups. Typically, they have a degree of polymerization ranging from 2 to 7 and are commonly referred to as xylobiose, xylotriose, and higher oligomers accordingly. XOS possess several notable physicochemical characteristics, including high water solubility and strong thermal stability. In addition, they demonstrate a wide range of biological activities, such as anti-inflammatory, antioxidant, antitumor, and antimicrobial effects, among others [15]. Disruptions in the balance of microbial communities, a state referred to as dysbiosis, are closely associated with a broad range of conditions, including colorectal cancer, non-alcoholic fatty liver disease (NAFLD), obesity, inflammatory bowel disease (IBD), and type 2 diabetes. Because the makeup of the gut microbiome can be shaped by nutritional intake, numerous dietary strategies have been developed to address these imbalances. Among these interventions, prebiotics represent a highly favorable option owing to their demonstrated efficacy and established safety profile [25].
Given their prebiotic properties and ability to influence gut microbial composition, xylo-oligosaccharides (XOS) have been widely studied for a range of health-promoting effects. The following sections summarize the key reported benefits of XOS in biological systems, with relevance to companion animal health.
II . Benefits of XOS
Gut Microbiota Modulation
In companion animals, the gastrointestinal microbiome plays a critical role in maintaining digestive efficiency, metabolic balance, and overall health status. Modulation of this microbial ecosystem through dietary prebiotics such as xylo-oligosaccharides (XOS) has gained increasing attention as a strategy to promote beneficial bacteria and improve gut functionality.
A study evaluated the impact of the prebiotic fiber xylooligosaccharides (XOS) on the intestinal microbiota and metabolic profiles of 24 healthy adult cats. The feline subjects were divided into three experimental treatments: a control group, a low-dose XOS group, and a high-dose XOS group. The results demonstrated that both dosage levels of XOS increased the populations of specific gut bacteria, including Blautia, Clostridium group XI, and Collinsella, while concurrently reducing Megasphaera and Bifidobacterium. Furthermore, the low-dose XOS intervention specifically increased the abundance of Streptococcus, Lactobacillus, and Catenibacterium, which was accompanied by an increase in fecal pH. This low-dose supplementation also successfully lowered a specific blood biomarker associated with lipid metabolism. The high-dose XOS group demonstrated a more pronounced shift in the intestinal microbiota, resulting in increased levels of Subdoligranulum, an unassigned genus of Ruminococcaceae, an Erysipelotrichaceae genus, and Lachnospiraceae. This higher dosage also successfully improved the overall diversity of the gut microbes. Overall, the study established that XOS modulates the feline gut microbiome and supports intestinal health, with higher and lower doses uniquely influencing different bacterial populations [27] . Another study reported that dietary supplementation with Xylo-oligosaccharides (XOS) optimizes gastrointestinal development, immune response, and growth metrics. Structurally, XOS strengthened the mucosal architecture of the small intestine by increasing villus height to expand the absorptive surface area, while also multiplying goblet cells to reinforce the protective mucus barrier. Additionally, whereas traditional antibiotic treatments compromised the intestinal ecosystem by reducing microbial diversity, XOS increased overall bacterial diversity. This prebiotic selectively enriched health-promoting Lactobacillus populations while suppressing opportunistic pathogens, including Escherichia-Shigella, Clostridium, and Terrisporobacter. Following this microbial shift, the microbiome fermented the XOS into beneficial short-chain fatty acids, which actively mitigate inflammation and provide a primary energy source for the cells of the intestinal lining. Consequently, the researchers concluded that XOS functions as an effective, natural alternative to conventional antibiotics by directly reinforcing both the physical structure and the microbial balance of the gut ecosystem [36]. Additionally, both XOS and GOS significantly reduced the populations of intestinal Listeria monocytogenes within the ileum of guinea pigs. This prebiotic intervention selectively stimulated the growth of Bifidobacteria and Lactobacilli, which are recognized for their ability to inhibit pathogenic bacteria [16]. Another study reported that xylo-oligosaccharides (XOS) have a targeted positive impact on gut microbiota composition. Laboratory (in vitro) tests showed that beneficial Bifidobacteria can readily use XOS as a nutrient source, whereas harmful bacteria like Escherichia coli and Clostridium species cannot metabolize it at all. In living systems (in vivo), regular dietary XOS intake was also shown to encourage the growth of Bifidobacteria populations in the intestine.This targeted bacterial expansion effectively reduced fecal pH levels and supported proper moisture retention within the stool to prevent digestive upset. Consequently, the authors concluded that XOS creates an optimal internal environment by actively accelerating the growth of protective microbes while starving out harmful, opportunistic pathogens [42]. Additionally, a research analyzed how swine fecal microbiota ferment various types of oligosaccharides. The findings revealed that large intestine microbes break down the XOS substrate much more thoroughly than the other tested oligosaccharides. Furthermore, the breakdown of XOS generated the greatest overall concentration of total short-chain fatty acids (SCFAs) out of all the oligosaccharides groups evaluated [9]. An 8-week clinical trial utilizing a randomized, double-blind, placebo-controlled setup confirmed that adult participants could easily tolerate xylo-oligosaccharide (XOS) while gaining digestive benefits. Daily intakes of either 1.4 grams or 2.8 grams successfully increased populations of helpful Bifidobacterium, showing a clear dose-dependent improvement favoring the larger amount. This 2.8 g/day protocol also boosted total anaerobic microbes along with the Bacteroides fragilis cluster. The researchers concluded that XOS serves as a safe intervention for enriching protective intestinal microbes, especially Bifidobacterium, without triggering adverse reactions. The data further indicated that a daily intake of 2.8 grams delivers superior efficacy compared to a 1.4-gram dose [28]. Overall, XOS have demonstrated the ability to optimize nutrient digestion and assimilation while simultaneously supporting systemic health by checking the multiplication of harmful pathogenic bacteria. The antimicrobial effects of XOs against pathogenic bacteria are mainly attributed to two key mechanisms. First, they promote the growth and colonization of beneficial probiotic bacteria along the intestinal lining. Second, they lower intestinal pH by stimulating the formation of organic acids such as lactic acid and acetic acid. Through these actions, XOs help protect against gastrointestinal infections, support normal fecal moisture balance, and reduce the risk of diarrhea. Additionally, besides limiting harmful enteric bacteria, XOs also reduce the generation of toxic metabolites such as amines [7].
Modulation of Immune Response
Companion animals possess an immune system that is strongly influenced by nutritional status and gut microbiota composition, particularly during early developmental stages. Prebiotic interventions such as XOS have been explored for their potential to enhance immune function and regulate inflammatory responses.
The immune system acts as an intricate, multi-tiered network responsible for both bodily defense and tissue recovery, making its functionality a primary metric for evaluating general well-being. Because this system is not fully developed during an animal's first year of life, young offspring face a heightened vulnerability to pathogens. To counteract this developmental window, mammals utilize passive immunity by delivering maternally derived antibodies (MDA) through the placenta and via colostrum or milk during nursing. Nevertheless, this temporary defense steadily declines as the animal grows [29]. The immune system undergoes important development during early life, and nutrition plays a major role in shaping its function. Certain nutrients can support immune health both directly, through their uptake and detection by immune cells, and indirectly, by influencing the interactions between the intestinal microbiota and the immune system. Studies have shown that compounds such as nucleotides, oligosaccharides, and vitamins may contribute positively to immune function. A 28-week study in kittens investigated the immune effects of a fortified diet enriched with xylo-oligosaccharides (XOS), short-chain fructooligosaccharides (scFOS), nucleotides, β-carotene, and vitamin E. Forty kittens were assigned either a standard control diet or the supplemented diet and were vaccinated against feline parvovirus and herpesvirus during the trial. Kittens fed the enriched diet developed stronger immune responses, demonstrated by higher antibody concentrations against both viruses than those in the control group. Furthermore, a higher percentage of the kittens consuming the enriched diet reached protective antibody thresholds and demonstrated an elevated response to the immunizations, coupled with increased serum IgM levels. Ultimately, the researchers determined that this specific blend of nutrients, which features XOS, aids immune system performance and boosts the effectiveness of vaccines in kittens [30] . An in vitro experiment examined the immunomodulatory effects of xylo-oligosaccharides (XOS), a prebiotic dietary ingredient, using RAW264.7 macrophage cells. In unstimulated cells, XOS concentrations ranging from 0.1 to 100 μg/mL induced the expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, and nitric oxide. Conversely, in lipopolysaccharide (LPS)-stimulated macrophages, XOS attenuated the production of these pro-inflammatory mediators in a dose-dependent manner while concurrently upregulating the anti-inflammatory cytokine IL-10, without inducing cytotoxicity. Prostaglandin E2 concentrations were not significantly altered. In conclusion, the data demonstrate that XOS possesses immunomodulatory properties characterized by the mitigation of excessive inflammation and the enhancement of anti-inflammatory pathways under induced inflammatory conditions. [17]. In another study, an in vivo reserach utilizing a murine model demonstrated that a diet enriched with 10% xylo-oligosaccharides (XOS) markedly elevated beneficial Bifidobacterium populations across the gastrointestinal tract, with the most pronounced increase occurring within the ileum. This microbial shift correlated with a downregulation of systemic inflammatory biomarkers, specifically characterized by diminished blood expression levels of IL-1β and IFN-γ. The researchers also noted that XOS supplementation accelerated the production of short-chain fatty acids (SCFAs), which likely served as the primary mechanism driving these anti-inflammatory outcomes. Within the intestinal tissue itself, the expression of the majority of immune-related genes remained unaltered, though select protective antimicrobial responses were activated. Collectively, these insights suggest that XOS is capable of mitigating low-grade systemic inflammation via augmented intestinal fermentation and elevated SCFA synthesis [18]. A randomized, double-blind, placebo-controlled trial involving 60 healthy adult subjects evaluated the physiological impacts of xylo-oligosaccharides (XOS) both independently and when co-administered with inulin over a 4-week intervention period. The findings revealed that monotherapy with XOS significantly increased protective Bifidobacterium populations and enhanced butyrate synthesis within the gastrointestinal tract. Furthermore, this standalone prebiotic treatment successfully suppressed the accumulation of specific detrimental metabolic byproducts, including p-cresol. When XOS was combined with inulin, there was a further rise in total short-chain fatty acid and propionate production. The combined supplementation also decreased circulating lipopolysaccharide (LPS) levels and reduced inflammatory activity in the blood, including lower IL-1β expression. Overall, the study suggested that XOS, particularly in combination with inulin, may promote a healthier gut microbial profile and help alleviate diet-associated inflammation in healthy adults [19]. An investigation utilizing a broiler chicken model evaluated the physiological outcomes of dietary xylo-oligosaccharides (XOS) in comparison to the antibiotic flavomycin (FLA) over a six-week intervention period. Supplementation with either XOS or FLA resulted in a statistically significant increase in the average daily weight gain of the subjects. Within the cecal microenvironment, XOS administration elevated the concentrations of the beneficial short-chain fatty acids (SCFAs) acetate and butyrate, whereas FLA treatment selectively increased propionate levels. With respect to immunological function, XOS supplementation elevated plasma IgG titers in 21-day-old broilers. Both the XOS and FLA dietary interventions downregulated the expression of specific intestinal pro-inflammatory genes, namely IFNγ, LITAF, and TLR5. In conclusion, these data demonstrate that the incorporation of dietary XOS enhances growth performance and attenuates localized intestinal inflammation in broiler chickens by stimulating favorable gastrointestinal fermentation and SCFA synthesis [20].
Antioxidant Activity
Oxidative stress, driven by excess reactive oxygen species, is a key contributor to cellular dysfunction in both companion animals and other biological systems. Xylo-oligosaccharides (XOS) have been reported to exhibit antioxidant potential by enhancing endogenous antioxidant defenses and reducing oxidative damage through free radical scavenging mechanisms.
In both acute and chronic pathologies, the concentration of free radicals typically escalates. Multiple key investigations have revealed that XOS displays potent antioxidant and free radical scavenging capabilities, pointing to its prospective utility in biomedical contexts [21, 22]. This scavenging capacity operates in a dose-dependent manner [23], an effect that is probably driven by the productive liberation of phenolic constituents and the subsequent migration of hydrogen atoms from these phenolic complexes to free radicals [24]. An investigation demonstrated that dietary supplementation with xylooligosaccharides (XOS) enhanced antioxidant capacity, immune profiles, and intestinal microflora structure in weaned piglets. XOS inclusion optimized antioxidant defense mechanisms by raising glutathione peroxidase activity and reducing malondialdehyde concentrations [31]. Another study reported that corn-derived xylooligosaccharides (XOS) exhibited antioxidant activity in vitro. Chemical analyses confirmed the presence of mainly six-unit xylose oligomers. XOS influenced the cellular antioxidant system by altering glutathione balance, contributing to reduced tumor cell survival [32].
Anti-obesity and Anti-diabetic Effects
While direct clinical data in companion animals is still emerging, research in murine models indicates that dietary prebiotics like xylo-oligosaccharides (XOS) can mitigate metabolic disorders like obesity and diabetes. By altering gut microbial composition to favor short-chain fatty acid production, these interventions regulate lipid synthesis genes, improve insulin sensitivity, and reduce visceral fat accumulation, offering promising metabolic applications for pet health.
Accumulating research indicates that alterations in the composition and functional capacity of the gastrointestinal microbiota are intrinsically linked to the pathogenesis of diabetes. Consequently, therapeutic strategies aimed at modulating the intestinal microbial architecture and its metabolic output particularly through the administration of prebiotics have gained significant traction. The intake of prebiotics influences the gut microbiota in a way that leads to the generation of beneficial microbial metabolites, particularly short-chain fatty acids. These compounds contribute to lowering blood glucose levels, improving insulin sensitivity, reducing inflammation, and enhancing the release of glucagon-like peptide 1 in the body. Together, these effects are associated with the improvement or remission of metabolic disorders [4]. Obesity is a metabolic disorder characterized by an excessive accumulation of adipose tissue resulting from a chronic positive energy imbalance. This condition is pathophysiologically linked to numerous comorbidities, including type 2 diabetes, cardiovascular diseases, and non-alcoholic fatty liver disease (NAFLD) [25, 26]. An in vivo study utilizing a murine model demonstrated that the dietary administration of xylo-oligosaccharides (XOS) markedly alters gastrointestinal microbiota composition and attenuates adiposity. Supplementation at both the 2.1% and 7.0% dose thresholds induced an elevation in cecal short-chain fatty acid (SCFA) synthesis alongside a reduction in the relative abundance of the phylum Actinobacteria. At the higher supplementation level (7.0%), XOS was associated with a decrease in visceral fat accumulation, along with reduced levels of the inflammatory marker monocyte chemoattractant protein-1 (MCP-1). It also led to a lower abundance of the dominant bacterial phyla Firmicutes and Bacteroidetes, which are often linked to obesity. However, neither the 2.1% nor the 7.0% dose produced noticeable changes in blood lipid levels or liver lipid profiles.The reduction in fat deposition appeared to be driven by suppressed expression of genes involved in fat cell formation and lipid synthesis, supporting the role of XOS as a prebiotic with potential metabolic benefits [33]. Another study showed that the prebiotic xylo-oligosaccharide (XOS) mitigated metabolic impairment triggered by a high-fat diet in a murine model. This intervention limited overall weight gain and epididymal fat accumulation, optimized serum lipid parameters (including triglycerides, total cholesterol, and LDL-C), decreased hepatic damage indicators (ALT and AST), and lowered inflammatory activity. Mechanistically, XOS was found to activate the AMPK signaling pathway, which promoted lipid breakdown by increasing the expression of genes involved in fatty acid oxidation, including CPT-1, PPAR-α, and CYP7A1, while simultaneously suppressing genes associated with fat synthesis and adipocyte formation such as ACC, C/EBPα, and LPL. Additionally, XOS improved intestinal barrier function by upregulating tight junction proteins (ZO-1, occludin, and claudin-1) and also influenced gut microbiota composition. Overall, these changes suggest a protective role of XOS against hyperlipidemia through regulation of the gut-liver axis [35]. Another study using a high-fat diet and streptozotocin-induced type 2 diabetes mouse model showed that xylo-oligosaccharide (XOS) supplementation improved overall metabolic health and reduced inflammation. It helped correct lipid imbalances, lowered systemic inflammatory responses, and protected against damage in the liver, kidneys, and pancreatic islets. Both doses tested (20 and 60 mg/kg/day) reshaped the gut microbial community, with increases in Bacteroides and Proteobacteria and a decline in Firmicutes. The higher dose showed stronger effects, particularly in improving glucose tolerance and enhancing insulin sensitivity. Overall, the findings indicate that XOS may support blood sugar control and reduce oxidative stress and inflammation, likely through modulation of gut microbiota [34].
Improvement in Growth Performance
Nutritional modulation of growth performance is closely linked to gut health, nutrient absorption efficiency, and systemic metabolic status, particularly in rapidly developing animals. Xylo-oligosaccharides (XOS) have been investigated for their potential to enhance growth performance by improving feed utilization, intestinal development, and associated physiological functions.
A study found that supplementing weaned piglet diets with xylo-oligosaccharide (XOS) improved both growth performance and intestinal health, serving as a potential alternative to chlortetracycline (CTC). Piglets fed 500 mg/kg XOS showed higher body weight and greater average daily weight gain, along with a reduced feed-to-gain ratio compared to the control group. XOS supplementation also enhanced intestinal structure by increasing villus height and the villus height-to-crypt depth ratio in the ileum, while also raising the number of goblet cells in the cecum [36]. An investigation demonstrated that dietary supplementation with xylooligosaccharides (XOS) enhanced growth outcomes, antioxidant capacity, immune profiles, and intestinal microflora structure in weaned piglets. Escalating XOS dosages boosted total body weight, average daily gain, and feed consumption, while concurrently lowering the feed conversion efficiency ratio.
Furthermore, XOS inclusion optimized antioxidant defense mechanisms by raising glutathione peroxidase activity and reducing malondialdehyde concentrations. Regarding systemic immunity, serum immunoglobulins (IgA, IgM, and IgG) along with the anti-inflammatory cytokine IL-10 were elevated, whereas the pro-inflammatory cytokines IL-1β and IL-6 were suppressed. Microbiota profiling revealed that XOS supplementation increased the abundance of beneficial genera such as Lactobacillus, Bifidobacterium, and Fusicatenibacter, along with higher concentrations of fecal short-chain fatty acids. Further correlation analysis indicated that these microbial changes were associated with improved growth performance, stronger immune responses, increased SCFA production, and reduced oxidative stress. Overall, the findings suggest that XOS supports growth and gut health by influencing microbial composition as well as antioxidant and immune-related pathways [31].
Oral Health Effects
The oral cavity hosts a complex microbial ecosystem where dysbiosis can contribute to opportunistic infections such as fungal overgrowth. Xylo-oligosaccharides (XOS) have been investigated for their potential antimicrobial effects in the oral environment by modulating microbial composition and reducing pathogen-associated imbalances.
A study found that dietary xylo-oligosaccharides (XOS) influenced the oral microbiota and helped reduce the severity of oropharyngeal candidiasis (OPC) in an immunosuppressed mouse model. Although XOS did not significantly increase oral Lactobacillus levels as initially expected, it did raise Bifidobacterium abundance while decreasing populations of enterococci and staphylococci. In mice affected by OPC, XOS intake weakened Candida albicans pathogenicity and helped correct microbial imbalance in the oral cavity, including a rise in lactobacilli and a reduction in enterococci on the mucosal surface. Overall, the results suggest that XOS may support a more stable and disease-resistant oral microbiome capable of limiting fungal overgrowth [37].
Anticancer Effects
Cancer is characterized by uncontrolled cellular proliferation and the potential for invasion and metastasis to distant tissues. Preclinical studies suggest that xylo-oligosaccharides (XOS) may exhibit anticancer potential through modulation of cellular signaling pathways, oxidative stress, and inflammatory responses. The principal causes of cancer involve the unchecked growth of abnormal cells that can either remain at the original mutation site or spread to other areas. Studies have demonstrated that XOS exposure is effective in preventing cancer [40, 41]. Additionally, XOS is utilized as a potential anticancer agent, particularly for colon and breast cancer [38]. A study reported that corn-derived xylooligosaccharides (XOS) exhibited antioxidant and antitumor activity in vitro. Chemical analyses confirmed the presence of mainly six-unit xylose oligomers. XOS reduced viability of tumor cell lines while showing cell-type dependent effects on cellular energy metabolism and organelle function. It also lowered inflammatory cytokine production in lipopolysaccharide-stimulated immune cells, suggesting involvement of Toll-like receptor 4 (TLR4)-related signaling. In addition, XOS influenced the cellular antioxidant system by altering glutathione balance, contributing to reduced tumor cell survival. Overall, the findings indicated that XOS may have potential disease-preventive and therapeutic effects [32]. A study demonstrated that acetylated xylo-oligosaccharide (AcXOS) obtained from hawthorn kernels possesses antitumor activity in both laboratory and animal models. In vitro experiments showed that AcXOS suppressed cancer cell migration and invasion while inducing apoptosis in Hep3B and RKO cell lines. In mice implanted with HCT116 colon cancer cells, oral AcXOS treatment significantly inhibited tumor growth. The underlying mechanism appeared to involve inhibition of the PI3K-Akt signaling pathway along with increased expression of apoptosis-related proteins such as Bax and cleaved caspase-3. In addition, AcXOS elevated fecal short-chain fatty acid concentrations and decreased histone deacetylase gene expression in colonic epithelial cells, indicating that gut microbiota-derived metabolites may contribute to its anticancer effects [39].
III. Conclusion
Xylo-oligosaccharides (XOS) represent a promising prebiotic with multifunctional biological activities relevant to companion animal health. Evidence from experimental and preclinical studies demonstrates that XOS can beneficially modulate gut microbiota composition, enhance short-chain fatty acid production, and support intestinal barrier integrity. In addition, XOS exhibits immunomodulatory, antioxidant, and metabolic regulatory properties, contributing to improved immune responses, reduced inflammation, and better metabolic outcomes. Emerging data also suggest potential roles in growth performance, oral health, and disease prevention, including anticancer effects. Collectively, these findings indicate that XOS may serve as a valuable functional ingredient in companion animal nutrition.
In alignment with its established functional benefits, XOS has been incorporated into India’s first cold-pressed dog food developed by Venttura. Venttura offers Junior- Turkey & Duck and Adult- Turkey & Duck variants. This represents a practical application of XOS in complete pet food systems, highlighting its integration into functional companion animal nutrition.
Frequently Asked Questions
1) What are xylo-oligosaccharides (XOS) and how do they work?
2) How does XOS support gut health in cats and dogs?
3) Can XOS help support immune function in pets?
4) How is XOS different from other prebiotics like FOS or inulin?
IV. References
1 - Salminen S, Collado MC, Endo A, Hill C, Lebeer S, Quigley EMM, Sanders ME, Shamir R, Swann JR, Szajewska H, Vinderola G. The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics. Nat Rev Gastroenterol Hepatol. 2021 Sep;18(9):649-667. doi: 10.1038/s41575-021-00440-6. Epub 2021 May 4. Erratum in: Nat Rev Gastroenterol Hepatol. 2021 Sep;18(9):671. doi: 10.1038/s41575-021-00481-x. Erratum in: Nat Rev Gastroenterol Hepatol. 2022 Aug;19(8):551.
https://pubmed.ncbi.nlm.nih.gov/33948025/
2 - Holscher HD. Dietary fiber and prebiotics and the gastrointestinal microbiota. Gut Microbes. 2017 Mar 4;8(2):172-184. doi: 10.1080/19490976.2017.1290756. Epub 2017 Feb 6. PMID: 28165863; PMCID: PMC5390821
https://pubmed.ncbi.nlm.nih.gov/28165863/
3 - 131. Althubiani, A.S.; Al-Ghamdi, S.B.; Samreen; Qais, F.A.; Khan, M.S.; Ahmad, I.; Malak, H.A. Plant-Derived Prebiotics and Its Health Benefits; Elsevier Inc.: Amsterdam, The Netherlands, 2018; ISBN 9780128146200.
4 - Megur A, Daliri EB, Baltriukienė D, Burokas A. Prebiotics as a Tool for the Prevention and Treatment of Obesity and Diabetes: Classification and Ability to Modulate the Gut Microbiota. Int J Mol Sci. 2022 May 29;23(11):6097. doi: 10.3390/ijms23116097. PMID: 35682774; PMCID: PMC9181475.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9181475/
5 - Gibson GR, Hutkins R, Sanders ME, Prescott SL, Reimer RA, Salminen SJ, Scott K, Stanton C, Swanson KS, Cani PD, Verbeke K, Reid G. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nat Rev Gastroenterol Hepatol. 2017 Aug;14(8):491-502. doi: 10.1038/nrgastro.2017.75. Epub 2017 Jun 14. PMID: 28611480.
https://pubmed.ncbi.nlm.nih.gov/28611480/
6 - Zentek J, Marquart B, Pietrzak T. Intestinal effects of mannanoligosaccharides, transgalactooligosaccharides, lactose and lactulose in dogs. J Nutr. 2002 Jun;132(6 Suppl 2):1682S-4S. doi: 10.1093/jn/132.6.1682S. PMID: 12042492.
https://pubmed.ncbi.nlm.nih.gov/12042492/
7 - Valladares-Diestra, K. K., de Souza Vandenberghe, L. P., Vieira, S., Goyzueta-Mamani, L. D., de Mattos, P. B. G., Manzoki, M. C., Soccol, V. T., & Soccol, C. R. (2023). The Potential of Xylooligosaccharides as Prebiotics and Their Sustainable Production from Agro-Industrial by-Products. Foods, 12(14), 2681. https://doi.org/10.3390/foods12142681
8 - Akpinar O, Erdogan K, Bostanci S. Production of xylooligosaccharides by controlled acid hydrolysis of lignocellulosic materials. Carbohydr Res. 2009 Mar 31;344(5):660-6. doi: 10.1016/j.carres.2009.01.015. Epub 2009 Jan 19. PMID: 19211099.
https://pubmed.ncbi.nlm.nih.gov/19211099/
9 - Smiricky-Tjardes MR, Flickinger EA, Grieshop CM, Bauer LL, Murphy MR, Fahey GC Jr. In vitro fermentation characteristics of selected oligosaccharides by swine fecal microflora. J Anim Sci. 2003 Oct;81(10):2505-14. doi: 10.2527/2003.81102505x. PMID: 14552378.
https://pubmed.ncbi.nlm.nih.gov/14552378/
10 - Yoo CG, Meng X, Pu Y, Ragauskas AJ. The critical role of lignin in lignocellulosic biomass conversion and recent pretreatment strategies: A comprehensive review. Bioresour Technol. 2020 Apr;301:122784. doi: 10.1016/j.biortech.2020.122784. Epub 2020 Jan 11. PMID: 31980318.
https://pubmed.ncbi.nlm.nih.gov/31980318/
11 - Rao, J., Lv, Z., Chen, G., & Peng, F. (2023). Hemicellulose: Structure, chemical modification, and application. Progress in Polymer Science, 140, Article 101675. https://doi.org/10.1016/j.progpolymsci.2023.101675
12 - Kaur, G., Kaur, P., Kaur, J., Singla, D., & Taggar, M. S. (2024). Xylanase, xylooligosaccharide and xylitol production from lignocellulosic biomass: Exploring biovalorization of xylan from a sustainable biorefinery perspective. Industrial Crops and Products, 215, Article 118610. https://doi.org/10.1016/j.indcrop.2024.118610
13 - Iwuozor, K. O., Adeniyi, A. G., Emenike, E. C., Ojeyemi, T., Egbemhenghe, A. U., Okorie, C. J., Ayoku, B. D., & Saliu, O. D. (2023). Prospects and challenges of utilizing sugarcane bagasse as a bio-coagulant precursor for water treatment. Biotechnology Reports, 39, Article e00805. https://doi.org/10.1016/j.btre.2023. e00805
https://pubmed.ncbi.nlm.nih.gov/37448785/
14 - Jain I, Kumar V, Satyanarayana T. Xylooligosaccharides: an economical prebiotic from agroresidues and their health benefits. Indian J Exp Biol. 2015 Mar;53(3):131-42. PMID: 25872243.
https://pubmed.ncbi.nlm.nih.gov/25872243/
15 - Chen Y, Xie Y, Ajuwon KM, Zhong R, Li T, Chen L, Zhang H, Beckers Y, Everaert N. Xylo-Oligosaccharides, Preparation and Application to Human and Animal Health: A Review. Front Nutr. 2021 Sep 8;8:731930. doi: 10.3389/fnut.2021.731930. PMID: 34568407; PMCID: PMC8458953.
https://pubmed.ncbi.nlm.nih.gov/34568407/
16 - Ebersbach T, Jørgensen JB, Heegaard PM, Lahtinen SJ, Ouwehand AC, Poulsen M, Frøkiaer H, Licht TR. Certain dietary carbohydrates promote Listeria infection in a guinea pig model, while others prevent it. Int J Food Microbiol. 2010 Jun 15;140(2-3):218-24. doi: 10.1016/j.ijfoodmicro.2010.03.030. Epub 2010 Mar 27. PMID: 20417983.
https://pubmed.ncbi.nlm.nih.gov/20417983/
17 -Chen H, Chen Y, Chang H. Immunomodulatory effects of xylooligosaccharides[J]. Food Sci Technol Res. (2012) 18:195 9. doi: 10.3136/fstr.18.195
https://www.researchgate.net/publication/270066163_Immunomodulatory_Effects_of_Xylooligosaccharides
18 - Hansen CH, Frøkiær H, Christensen AG, Bergström A, Licht TR, Hansen AK, Metzdorff SB. Dietary xylooligosaccharide downregulates IFN-γ and the low-grade inflammatory cytokine IL-1β systemically in mice. J Nutr. 2013 Apr;143(4):533-40. doi: 10.3945/jn.112.172361. Epub 2013 Feb 20. PMID: 23427328.
https://pubmed.ncbi.nlm.nih.gov/23427328/
19 - Lecerf JM, Dépeint F, Clerc E, Dugenet Y, Niamba CN, Rhazi L, Cayzeele A, Abdelnour G, Jaruga A, Younes H, Jacobs H, Lambrey G, Abdelnour AM, Pouillart PR. Xylo-oligosaccharide (XOS) in combination with inulin modulates both the intestinal environment and immune status in healthy subjects, while XOS alone only shows prebiotic properties. Br J Nutr. 2012 Nov 28;108(10):1847-58. doi: 10.1017/S0007114511007252. Epub 2012 Jan 23. PMID: 22264499.
https://pubmed.ncbi.nlm.nih.gov/22264499/
20 - Yuan L, Li W, Huo Q, Du C, Wang Z, Yi B, Wang M. Effects of xylo-oligosaccharide and flavomycin on the immune function of broiler chickens. PeerJ. 2018 Mar 5;6:e4435. doi: 10.7717/peerj.4435. PMID: 29527412; PMCID: PMC5842763.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5842763/
21 - Yu X, Yin J, Li L, Luan C, Zhang J, Zhao C, Li S. Prebiotic Potential of Xylooligosaccharides Derived from Corn Cobs and Their In Vitro Antioxidant Activity When Combined with Lactobacillus. J Microbiol Biotechnol. 2015 Jul;25(7):1084-92. doi: 10.4014/jmb.1501.01022. PMID: 25791856.
https://pubmed.ncbi.nlm.nih.gov/25791856/
22 - Rashad MM, Mahmoud AE, Nooman MU, Mahmoud HA, Keshta AT. Production of antioxidant xylooligosaccharides from lignocellulosic materials using bacillus amyloliquifaciens NRRL B-14393 xylanase. J App Pharm Sci. (2016) 6:30–6. doi: 10.7324/JAPS.2016.60606
https://japsonline.com/abstract.php?article_id=1890&sts=2
23 -Gowdhaman D, Ponnusami V. Production and optimization of xylooligosaccharides from corncob by Bacillus aerophilus KGJ2 xylanase and its antioxidant potential. Int J Biol Macromol. 2015 Aug;79:595-600. doi: 10.1016/j.ijbiomac.2015.05.046. Epub 2015 May 30. PMID: 26038103.
https://pubmed.ncbi.nlm.nih.gov/26038103/
24 - Huang D, Ou B, Prior RL. The chemistry behind antioxidant capacity assays. J Agric Food Chem. 2005 Mar 23;53(6):1841-56. doi: 10.1021/jf030723c. PMID: 15769103.
https://pubmed.ncbi.nlm.nih.gov/15769103/
25 - Nogueira-Prieto NM, Ansín-Vallejo C, Becerra-Fernández M, González-Siso MI. A review of the capacity of xylooligosaccharides to modulate gut microbiota and promote health. Food Funct. 2025 Jun 16;16(12):4654-4672. doi: 10.1039/d5fo00169b. PMID: 40470881.
https://pubmed.ncbi.nlm.nih.gov/40470881/
26 - Benítez-Páez A, Kjølbæk L, Gómez Del Pulgar EM, Brahe LK, Astrup A, Matysik S, Schött HF, Krautbauer S, Liebisch G, Boberska J, Claus S, Rampelli S, Brigidi P, Larsen LH, Sanz Y. A Multi-omics Approach to Unraveling the Microbiome-Mediated Effects of Arabinoxylan Oligosaccharides in Overweight Humans. mSystems. 2019 May 28;4(4):e00209-19. doi: 10.1128/mSystems.00209-19. PMID: 31138673; PMCID: PMC6538848.
https://pubmed.ncbi.nlm.nih.gov/31138673/
27 - Lyu Y, Debevere S, Bourgeois H, Ran M, Broeckx BJG, Vanhaecke L, Wiele TV, Hesta M. Dose-Dependent Effects of Dietary Xylooligosaccharides Supplementation on Microbiota, Fermentation and Metabolism in Healthy Adult Cats. Molecules. 2020 Oct 29;25(21):5030. doi: 10.3390/molecules25215030. PMID: 33138291; PMCID: PMC7662210.
https://pubmed.ncbi.nlm.nih.gov/33138291/
28 - Finegold SM, Li Z, Summanen PH, Downes J, Thames G, Corbett K, Dowd S, Krak M, Heber D. Xylooligosaccharide increases bifidobacteria but not lactobacilli in human gut microbiota. Food Funct. 2014 Mar;5(3):436-45. doi: 10.1039/c3fo60348b. PMID: 24513849.
https://pubmed.ncbi.nlm.nih.gov/24513849/
29 - Calder PC, Jackson AA. Undernutrition, infection and immune function. Nutrition Research Reviews. 2000;13(1):3-29. doi:10.1079/095442200108728981
30 - Atwal J, Joly W, Bednall R, Albanese F, Farquhar M, Holcombe LJ, Watson P, Harrison M. Dietary Supplementation with Nucleotides, Short-Chain Fructooligosaccharides, Xylooligosaccharides, Beta-Carotene and Vitamin E Influences Immune Function in Kittens. Animals (Basel). 2023 Dec 2;13(23):3734. doi: 10.3390/ani13233734. PMID: 38067085; PMCID: PMC10705356.
https://pubmed.ncbi.nlm.nih.gov/38067085/
31 - Pang J, Zhou X, Ye H, Wu Y, Wang Z, Lu D, Wang J, Han D. The High Level of Xylooligosaccharides Improves Growth Performance in Weaned Piglets by Increasing Antioxidant Activity, Enhancing Immune Function, and Modulating Gut Microbiota. Front Nutr. 2021 Dec 6;8:764556. doi: 10.3389/fnut.2021.764556. PMID: 34938759; PMCID: PMC8685398.
https://pubmed.ncbi.nlm.nih.gov/34938759/
32 - Batsalova T, Georgiev Y, Moten D, Teneva I, Dzhambazov B. Natural Xylooligosaccharides Exert Antitumor Activity via Modulation of Cellular Antioxidant State and TLR4. Int J Mol Sci. 2022 Sep 9;23(18):10430. doi: 10.3390/ijms231810430. PMID: 36142342; PMCID: PMC9499660.
https://pubmed.ncbi.nlm.nih.gov/36142342/
33 - Long JianFeng,Long JianFeng and Yang JiePing,Yang JiePing and Henning,S. M. and Woo ShihLung,Woo ShihLung and Hsu,M. and Chan,B. and Heber,D. and Li ZhaoPing,Li ZhaoPing, 20193156813, English, Journal article, UK, doi:10.1016/j.jff.2018.10.035, 1756-4646, 52, Oxford, Journal of Functional Foods, (138–146), Elsevier Ltd, Xylooligosaccharide supplementation decreases visceral fat accumulation and modulates cecum microbiome in mice., (2019)
https://www.cabidigitallibrary.org/doi/full/10.5555/20193156813
34 - Li, X., Xia, X., Cai, Z., Pang, X., Sun, J., & Lu, Y. (2025). Xylose-Oligosaccharide Alleviating Type 2 Diabetes in Mice via Reducing Blood Glucose, Oxidative Stress, Inflammation and Regulating Intestinal Microbiota. Foods, 14(12), 2093. https://doi.org/10.3390/foods14122093
35 - Fei Y, Wang Y, Pang Y, Wang W, Zhu D, Xie M, Lan S, Wang Z. Xylooligosaccharide Modulates Gut Microbiota and Alleviates Colonic Inflammation Caused by High Fat Diet Induced Obesity. Front Physiol. 2020 Jan 22;10:1601. doi: 10.3389/fphys.2019.01601. PMID: 32038285; PMCID: PMC6987399.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6987399/
36 - Chen Y, Xie Y, Zhong R, Liu L, Lin C, Xiao L, Chen L, Zhang H, Beckers Y, Everaert N. Effects of Xylo-Oligosaccharides on Growth and Gut Microbiota as Potential Replacements for Antibiotic in Weaning Piglets. Front Microbiol. 2021 Feb 25;12:641172. doi: 10.3389/fmicb.2021.641172. PMID: 33717037; PMCID: PMC7947891.
https://pubmed.ncbi.nlm.nih.gov/33717037/
37 - Vazquez-Munoz R, Thompson A, Sobue T, Dongari-Bagtzoglou A. A prebiotic diet modulates the oral microbiome composition and results in the attenuation of oropharyngeal candidiasis in mice. Microbiol Spectr. 2023 Oct 17;11(5):e0173423. doi: 10.1128/spectrum.01734-23. Epub 2023 Sep 6. PMID: 37671879; PMCID: PMC10580959.
https://pubmed.ncbi.nlm.nih.gov/37671879/
38- Gupta, Praveen Kumar & Agrawal, Pushpa & Hedge, Prabha & Akhtar, Mohd Sayeed. (2018). Xylooligosaccharides and Their Anticancer Potential: An Update. 10.1007/978-981-10-8064-7_11. - https://www.researchgate.net/publication/326132868_Xylooligosaccharides_and_Their_Anticancer_Potential_An_Update
39 - Yuncong Xu, Chunhua Zhu, Yuntao Lu, Shaoqing Yang, Jing Fang, Zhengqiang Jiang,Acetylated xylo-oligosaccharide from Hawthorn kernels inhibits colon cancer cells in vitro and in vivo,
Journal of Functional Foods,Volume 102,2023,105436,ISSN 1756-4646,
https://www.sciencedirect.com/science/article/pii/S1756464623000361?via%3Dihub
40 - Maeda, Reiko & Ida, Tomoaki & Ihara, Hideshi & Sakamoto, Tatsuji. (2012). Induction of Apoptosis in MCF-7 Cells by β-1,3-Xylooligosaccharides Prepared from Caulerpa lentillifera. Bioscience, biotechnology, and biochemistry. 76. 1032-4. 10.1271/bbb.120016.
https://www.researchgate.net/publication/228081193_Induction_of_Apoptosis_in_MCF-7_Cells_by_b-13-Xylooligosaccharides_Prepared_from_Caulerpa_lentillifera
41 - Howe, G. R., Benito, E., Castelleto, R., Cornée, J., Estève, J., Gallagher, R. P., Iscovich, J. M., Deng-ao, J., Kaaks, R., & Kune, G. A. (1992). Dietary intake of fiber and decreased risk of cancers of the colon and rectum: evidence from the combined analysis of 13 case-control studies. Journal of the National Cancer Institute, 84(24), 1887–1896. https://doi.org/10.1093/jnci/84.24.1887
42 - Okazaki, M., Fujikawa, S., & Matsumoto, N. (1990). Effect of Xylooligosaccharide on the Growth of Bifidobacteria. Bifidobacteria and Microflora, 9, 77-86.