Bacteroides fragilis Protects Against Antibiotic-Associated Diarrhea in Rats by Modulating Intestinal Defenses

Abstract

Antibiotic-associated diarrhea (AAD) is iatrogenic diarrhea characterized by disruption of the gut microbiota. Probiotics are routinely used to treat AAD in clinical practice; however, the effectiveness and mechanisms by which probiotics alleviate symptoms remain poorly understood. We previously isolated a non-toxic Bacteroides fragilis strain ZY-312, which has been verified to be beneficial in certain infection disorders. However, the precise role of this commensal bacterium in AAD is unknown. In this study, we successfully established an AAD rat model by exposing rats to appropriate antibiotics. These rats developed diarrhea symptoms and showed alterations in their intestinal microbiota, including overgrowth of some pathogenic bacteria. In addition, gastrointestinal barrier defects, indicated by compromised aquaporin expression, aberrant tight junction proteins, and decreased abundance of mucus-filled goblet cells, were also detected in ADD rats compared with control animals. Of note, oral treatment with B. fragilis strain ZY-312 ameliorated AAD-related diarrhea symptoms by increasing the abundance of specific commensal microbiota. Interestingly, we demonstrated that these changes were coincident with the restoration of intestinal barrier function and enterocyte regeneration in AAD rats. In summary, we identified a potential probiotic therapeutic strategy for AAD and identified the vital roles of B. fragilis strain ZY-312 in modulating the colonic bacterial community and participating in microbiota-mediated epithelial cell proliferation and differentiation.

<i>Bifidobacterium bifidum</i> G9-1 ameliorates soft feces induced by metformin without affecting its antihyperglycemic action

“…In our experiments, in addition to confirming that soft feces (increased fecal water content) was induced by the oral administration of metformin by gavage three times per day, we also confirmed changes in the gut microbiota, especially a tendency for a decrease in Lactobacillus species and a significant increase in Staphylococcus species. A decrease in Lactobacillus species and an increase in Staphylococcus species have also been confirmed for antibiotic-associated diarrhea (AAD) [ 14 ]. Furthermore, other studies have suggested that Lactobacillus administration improves AAD [ 15 ] and that the presence of Staphylococcus species is related to AAD [ 16 ].…”

In vivo Imaging of a Novel Strain of Bacteroides fragilis via Metabolic Labeling

“…Furthermore, ZY-312 has been shown to be able to inhibit the growth and adhesion of Vibrio parahaemolyticus ( V. parahaemolyticus ) in vitro and protect both RAW 264.7 and LoVo cells from damage caused by V. parahaemolyticus ( Li et al, 2017 ). Recently, we discovered the modulatory effect of ZY-312 on gut microbiota in rats, which contributes to the amelioration of antibiotic-associated diarrhea ( Zhang et al, 2018 ). In general, ZY-312 has the potential to become the first probiotic representative of the dominant Bacteroidetes phylum.…”

Personalized Probiotics Based on Phenotypes and Dietary Habit: A Critical Evaluation

“…GI commensal microbiota profile (enterotype) varied across geographical regions in a continuous matter [17][18][19]. It is apparent that the GI microenvironment and microbial community among Southeast Asian are not favourable for the establishment and proliferation of Bifidobacterium and Bacteroides, both of each have been suggested to play major roles in maintenance of health and are probiotics [7,[20][21][22][23]. It is reasonable to assume that Bifidobacterium and Bacteroides probiotics may need to be administered together with prebiotics (as synbiotic) for people in the South-East Asian.…”

“…It is therefore not surprising that beneficial effects of complex carbohydrate utilizing probiotics, such as Bifidobacterium spp. are amplified among East Asian [18,22] while meat-fat eating European and American may benefit from Bacteroides probiotics [21,23,55]. Selected strains of the respective bacteria group may serve as potent probiotics, if they are not already pleasant among the commensals, for people of different dietary habit.…”

“…Fermentation production of short chain fatty acids, such as butyric acid from fibre and oligosaccharides are assumed beneficial [56,57]. Short-chain-fatty acids and other microbial derived metabolites, such as bile acid derivatives [23] and trimethylamines [58] are also communication signals modulating host physiological functions. Typical Asian diets are high in fibre and carbohydrate as compared with typical Western diet, and presumably lead to high production of short-chain-fatty-acids (SCFAs) in their gut [59].…”