دانلود رایگان مقاله تجزیه و تحلیل تخمیر صمغ گوار تجزیه شده در شرایط آزمایشگاهی

Abstract

Background Prebiotic dietary fibers resist digestion in the upper gastrointestinal tract and allow for stimulation of bacteria in the distal intestine and colon. Stimulation of bacteria among different individuals varies greatly, depending on a wide range of variables. Objective To determine the range of differences in response between individuals, a preclinical in vitro fermentation was conducted with six fecal donors. The primary objective was to compare the fecal microbiota of six individuals at baseline, 12 h and 24 h post-exposure to partially hydrolyzed guar gum (PHGG). Method Fecal donations were collected from six healthy individuals consuming a non-specific Western diet, free of antibiotic treatments in the past year, not affected by any GI diseases and not consuming any probiotic or prebiotic supplements. Fecal samples were exposed to 0.5 g of PHGG and measured for bacterial changes at 0, 12 and 24 h based on 16S rRNA sequencing. Results Parabacteroides increased from 3.48% of sequence reads to 10.62% of sequence reads after 24 h (p = 0.0181) and Bacteroidetes increased from 45.89% of sequence reads to 50.29% of sequence reads (p = 0.0008). Conclusions PHGG stimulates growth of Parabacteroides, a genus of bacteria that have been inversely associated with IBS and ulcerative colitis. PHGG provides stimulation of beneficial Bacteroidetes (Bacteroides and Parabacteroides), which may be correlated with many positive health markers and outcomes. PHGG is a prebiotic dietary fiber that is readily fermentable.

5. Discussion

The increase of Parabacteroides was the most significant increase among all identified taxa, increasing from 3.48% of sequence reads at baseline to 10.62% of sequence reads after 24 h of fermentation. In a clinical study, oral administration of P. distasonis has been shown to reduce severity of intestinal inflammation in induced acute and chronic colitis in murine models due to the modulation of both immunity and microbiota factors [28]. Parabacteroides has been identified as one of the most abundant genera of bacteria in the human gastrointestinal tract [29]. Parabacteroides has also been shown to be present in higher concentrations in healthy controls compared to patients with IBS or ulcerative colitis, and it has been speculated that this genera of bacteria may play an influential role in the pathogenesis of both diseases [30]. Parabacteroides stimulation has been considered to have a prebiotic effect due to their preference to perform saccharolytic activity instead of proteolytic activity [8,31].