Xylooligosaccharide increases bifidobacteria but not lactobacilli in human gut microbiota

Abstract

This study was conducted to determine the tolerance and effects of the prebiotic xylooligosaccharide (XOS) on the composition of human colonic microbiota, pH and short chain fatty acids (SCFA) in order to determine whether significant changes in the microbiota would be achievable without side effects. Healthy adult subjects (n = 32) were recruited in a double-blind, randomized, placebo-controlled study. Subjects received 1.4 g XOS, 2.8 g XOS or placebo in daily doses. The study consisted of a 2 week run-in, an 8 week intervention, and a 2 week washout phase. Stool samples were collected at baseline, after 4 and 8 weeks of intervention and 2 weeks after cessation of intervention. Samples were subjected to culture, pyrosequencing of community DNA, pH and SCFA analyses. Tolerance was evaluated by daily symptom charts. XOS was tolerated without significant gastrointestinal side effects. Bifidobacterium counts increased in both XOS groups compared to the placebo subjects, the 2.8 g per day group showed significantly greater increases than the 1.4 g per day group. Total anaerobic counts and Bacteroides fragilis group counts were significantly higher in the 2.8 g per day XOS group. There were no significant differences in the counts of Lactobacillus, Enterobacteriaceae and Clostridium between the three groups. XOS intervention had no significant effect on stool pH, SCFA or lactic acid. Pyrosequencing showed no notable shifts in bacterial diversity. XOS supplementation may be beneficial to gastrointestinal microbiota and 2.8 g per day may be more effective than 1.4 g per day. The low dose required and lack of gastrointestinal side effects makes the use of XOS as a food supplement feasible.

Relative fermentation of oligosaccharides from human milk and plants by gut microbes

“…Notable exceptions are the ability of Bacteroides and Clostridium butyricum to utilize XOS [47] in vitro. Consistent with these in vitro results, consumption of XOS by healthy adults increases numbers of Bifidobacteria without increasing counts of Lactobacili [25]. 2′-FL, an isolated oligosaccharide that is a major component of the total HMOS, exhibits prebiotic effects [9,12,17,29,40,48].…”

“…XOS afforded growth of B. longum, but not of L. acidophilus. Previously, XOS were metabolized by the majority of Bifidobacteria tested, but not by other bacteria, including L. acidophilus [25]. Notable exceptions are the ability of Bacteroides and Clostridium butyricum to utilize XOS [47] in vitro.…”

“…These plant glycans include gluco-manno-oligosaccharides (GMOS) [23], xylo-oligosaccharides (XOS) [24,25], and cellobiose (CBS) [26]. These oligosaccharides occur at relatively low levels naturally, but are now synthesized for dietary use.…”

Recent developments in prebiotics to selectively impact beneficial microbes and promote intestinal health

“…They can be obtained either from corn cobs or from wheat arabinoxylans by hydrolysis [33]. Corn cob derived XOS has been used in a human volunteer study [43], where it was fed to 32 adult subjects. Subjects received either 1.4 g XOS, 2.8 g XOS or maltodextrin placebo per day for 8 weeks.…”

The Role of Supplemental Complex Dietary Carbohydrates and Gut Microbiota in Promoting Cardiometabolic and Immunological Health in Obesity: Lessons from Healthy Non-Obese Individuals

“…Most prebiotics are already included in the diet as they are naturally present in several types of food [e.g., legumes, wheat, rye, and onions (64, 65)], and are, therefore, considered to be part of a diet that contributes to the maintenance of sustainable health (66–68). Of note, although usually ignored in research reports, the (excessive) use of prebiotics could eventually lead to undesirable effects like excessive flatus, borborygmi, abdominal pain, and diarrhea (69, 70).…”