Probiotic Bifidobacterium strains and galactooligosaccharides improve intestinal barrier function in obese adults but show no synergism when used together as synbiotics

Abstract

BackgroundOne way to improve both the ecological performance and functionality of probiotic bacteria is by combining them with a prebiotic in the form of a synbiotic. However, the degree to which such synbiotic formulations improve probiotic strain functionality in humans has not been tested systematically. Our goal was to use a randomized, double-blind, placebo-controlled, parallel-arm clinical trial in obese humans to compare the ecological and physiological impact of the prebiotic galactooligosaccharides (GOS) and the probiotic strains Bifidobacterium adolescentis IVS-1 (autochthonous and selected via in vivo selection) and Bifidobacterium lactis BB-12 (commercial probiotic allochthonous to the human gut) when used on their own or as synbiotic combinations. After 3 weeks of consumption, strain-specific quantitative real-time PCR and 16S rRNA gene sequencing were performed on fecal samples to assess changes in the microbiota. Intestinal permeability was determined by measuring sugar recovery in urine by GC after consumption of a sugar mixture. Serum-based endotoxin exposure was also assessed.ResultsIVS-1 reached significantly higher cell numbers in fecal samples than BB-12 (P < 0.01) and, remarkably, its administration induced an increase in total bifidobacteria that was comparable to that of GOS. Although GOS showed a clear bifidogenic effect on the resident gut microbiota, both probiotic strains showed only a non-significant trend of higher fecal cell numbers when administered with GOS. Post-aspirin sucralose:lactulose ratios were reduced in groups IVS-1 (P = 0.050), IVS-1 + GOS (P = 0.022), and GOS (P = 0.010), while sucralose excretion was reduced with BB-12 (P = 0.002) and GOS (P = 0.020), indicating improvements in colonic permeability but no synergistic effects. No changes in markers of endotoxemia were observed.ConclusionThis study demonstrated that “autochthony” of the probiotic strain has a larger effect on ecological performance than the provision of a prebiotic substrate, likely due to competitive interactions with members of the resident microbiota. Although the synbiotic combinations tested in this study did not demonstrate functional synergism, our findings clearly showed that the pro- and prebiotic components by themselves improved markers of colonic permeability, providing a rational for their use in pathologies with an underlying leakiness of the gut.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0494-4) contains supplementary material, which is available to authorized users.

Probiotics and prebiotics in intestinal health and disease: from biology to the clinic

“…As discussed earlier, prebiotic intervention results in the elaboration of SCFAs that can act to improve barrier function in the gut and prebiotic intervention with GOS has shown improvements in barrier function in vivo. 115 Impaired barrier function can allow translocation of inflammatory mediators such as bacterial lipopolysaccharide (LPS) from the gut into systemic circulation, which has been termed metabolic endotoxaemia 116 and has been suggested to be a causative factor in diabetes and obesity according to evidence, albeit from studies in mice. 117,118 .…”

A human-origin probiotic cocktail ameliorates aging-related leaky gut and inflammation via modulating the microbiota/taurine/tight junction axis

“…Although several other probiotics and commensal strains are also known to modulate gut microbiota and have shown beneficial effects on host health (3,54,55), their mechanisms of actions are not clear. Some probiotic strains are known to modulate immune cells to suppress inflammation, whereas others have been shown to enhance the intestinal barrier to reduce inflammation by reducing nonspecific leakiness of inflammatory substances from gut to immune sites (18,19). Nevertheless, these results remain correlative, as leaky gut induces inflammation and increased inflammation also promotes derangements in intestinal barrier functions to increase leakiness (20,21).…”

“…Probiotics are one of the most accepted strategies to modulate the gut microbiota and normalize dysbiosis (13)(14)(15)(16)(17); therefore, we posit that probiotic therapy can maintain healthy gut microbiota and reduce leaky gut and inflammation. Several preclinical studies have shown that some specific probiotic strains may improve intestinal permeability homeostasis (18,19) and inflammation (20,21). Multiple studies also suggest that probiotics are beneficial for several human diseases, including obesity and diabetes (13)(14)(15)(16)(17)(21)(22)(23); however, the origin of such probiotics remains largely unknown.…”

Effects of synbiotics containing Bifidobacterium animalis subsp. lactis GCL2505 and inulin on intestinal bifidobacteria: A randomized, placebo‐controlled, crossover study

“…The combination of both probiotics and prebiotics is called synbiotics (Gibson & Roberfroid, 1995). The ingestion of synbiotics is also expected to lead to a large increase in the number of bifidobacteria in the intestinal tract (Childs et al, 2014;Krumbeck et al, 2018;Macfarlane, Cleary, Bahrami, Reynolds, & Macfarlane, 2013;Shioiri et al, 2006). Unfortunately, because previous reports evaluated the bifidogenic effects of synbiotics compared with only placebo, not with probiotics directly, and studies did not result in a significant increase in the number of bifidobacteria compared with probiotics, it has not been shown definitively that synbiotics are clearly better than probiotics or prebiotics at increasing the number of bifidobacteria in the gut.…”