Supplemental Bacillus subtilis DSM 32315 manipulates intestinal structure and microbial composition in broiler chickens

Abstract

Knowledge about the modulation of gut microbiota improves our understanding of the underlying mechanism by which probiotic treatment benefits the chickens. This study examined the effects of Bacillus subtilis DSM 32315 on intestinal structure and microbial composition in broilers. Broiler chicks were fed basal diets without or with B. subtilis supplementation (1.0 × 109 spores/kg of diet). Supplemental B. subtilis increased average body weight and average daily gain, as well as elevated villus height and villus height to crypt depth ratio of ileum in broilers. Multi-dimension analysis showed a certain degree of separation between the cecal microbiota from treatment and control groups. Increased Firmicutes abundance and reduced Bacteroidetes abundance in cecum were observed responded to B. subtilis addition, which also increased the abundances of Christensenellaceae and Caulobacteraceae, and simultaneously decreased the abundances of potentially harmful bacteria such as Vampirovibrio, Escherichia/Shigella and Parabacteroides. Network analysis signified that B. subtilis addition improved the interaction pattern within cecal microbiota of broilers, however, it exerted little influence on the metabolic pathways of cecal microbiota by comparison of the functional prediction of metagenomes. In conclusion, supplemental B. subtilis DSM 32315 improved growth performance and intestinal structure of broilers, which could be at least partially responsible by the manipulation of cecal microbial composition.

Dietary Bacillus spp. enhanced growth and disease resistance of weaned pigs by modulating intestinal microbiota and systemic immunity

“…In addition, post-weaning diarrhea is also associated with increased gut permeability due to the disturbed tight junction protein expression in the small intestine [34]. In the current study, supplementation of Bacillus subtilis DSM 32540 increased ileal villi height and duodenal crypt depth compared with pigs in the control group on d 21 PI, which was also reported in other studies where the same Bacillus subtilis strain was used in pigs and chickens under normal housing conditions [45,46]. The villus is populated by differentiated enterocytes that have distinctive absorptive and secretary functions, while the crypt is populated by stem cells that are rapidly proliferating and differentiating [47].…”

Bacillus subtilis Strain DSM 29784 Modulates the Cecal Microbiome, Concentration of Short-Chain Fatty Acids, and Apparent Retention of Dietary Components in Shaver White Chickens during Grower, Developer, and Laying Phases

“…It is reported that B. subtilis vegetative cells are present in the gastrointestinal tracts of birds as normal residents (75). However, a decrease in the relative abundance of Bacilli in the probiotic-fed groups compared to the control, which was observed in the developer and layer phases, may suggest a feedback of lessened potential pathogens after its supplementation (72,76), possibly creating a conducive environment in modifying the structure of the cecal microbiome. On the other hand, probiotics containing dead organisms have also been shown to express beneficial effects (77,78), such as by inducing specific immune responses based on the ability of immune cells to recognize individual bacterial cell structural components (79).…”

Dietary Supplementation With Bacillus subtilis Direct-Fed Microbials Alters Chicken Intestinal Metabolite Levels

“…and reduced Escherichia coli levels in the intestinal contents of DFMsupplemented birds, compared with controls. Increased growth performance, nutrient utilization, and intestinal villus/crypt morphometry, as well as altered composition of gut microbiota, also were observed in chickens orally administered with Bacillus DFMs, compared with controls (32)(33)(34)(35).…”