Substrate For Bacterial Fermentation Research Articles

The Effect of Prebiotic Supplements on the Gastrointestinal Microbiota and Associated Health Parameters in Pigs.

Establishing a balanced and diverse microbiota in the GIT of pigs is crucial for optimizing health and performance throughout the production cycle. The post-weaning period is a critical phase, as it is often associated with dysbiosis, intestinal dysfunction and poor performance. Traditionally, intestinal dysfunctions associated with weaning have been alleviated using antibiotics and/or antimicrobials. However, increasing concerns regarding the prevalence of antimicrobial-resistant bacteria has prompted an industry-wide drive towards identifying natural sustainable dietary alternatives. Modulating the microbiota through dietary intervention can improve animal health by increasing the production of health-promoting metabolites associated with the improved microbiota, while limiting the establishment and proliferation of pathogenic bacteria. Prebiotics are a class of bioactive compounds that resist digestion by gastrointestinal enzymes, but which can still be utilized by beneficial microbes within the GIT. Prebiotics are a substrate for these beneficial microbes and therefore enhance their proliferation and abundance, leading to the increased production of health-promoting metabolites and suppression of pathogenic proliferation in the GIT. There are a vast range of prebiotics, including carbohydrates such as non-digestible oligosaccharides, beta-glucans, resistant starch, and inulin. Furthermore, the definition of a prebiotic has recently expanded to include novel prebiotics such as peptides and amino acids. A novel class of -biotics, referred to as "stimbiotics", was recently suggested. This bioactive group has microbiota-modulating capabilities and promotes increases in short-chain fatty acid (SCFA) production in a disproportionally greater manner than if they were merely substrates for bacterial fermentation. The aim of this review is to characterize the different prebiotics, detail the current understating of stimbiotics, and outline how supplementation to pigs at different stages of development and production can potentially modulate the GIT microbiota and subsequently improve the health and performance of animals.

THE EFFECTS OF COPRA-MANNO-OLIGOSACCHARIDE ON BACTERIUM AGGREGATION ACTIVITY AND MICROBIOLOGICAL CHANGES IN A SIMULATED DIGESTIVE TRACT

This study aimed to present the interaction of Mannooligosaccharide (MOS) produced by optimum hydrolytic reaction of the recombinant mannanase KMAN treated defatted copra meal (DCM) to bacterial aggregation activity and to microbial changes in simulated gastro-intestinal tract which were two main functions of prebiotics as a decoy receptor and a substrate for bacterial fermentation, respectively. The suitable ratio of KMAN and DCM (0.8U:1mg) achieved high DCM hydrolysate-MOS production of 2.13-2.38 g/l during 6-24 h. It enhanced Limosilactobacillus reuteri KUB-AC5 growth for 0.32-0.33 h-1 and accelerated autoaggregation activity by 95.86% and 62.89% at 37 and 42°C, respectively. It decreased autoaggregation activities of Salmonella Enteritidis DMST17368 by 75.03-81.66%, and Lactobacillus johnsonii KUNN19-2 by 38.68-55.63% at 24 h. By simulated human GI model, COPRA-MOS significantly enhanced only Clostridium coccoides-Eubacterium rectale at 24 h with high acetic acid concentration of 87.43 mM. Whereas the chicken simulation model led to low abundance of Enterobacteriaceae but a higher Lactobacillus population with acetic acid concentration of 22.94 mM. These results suggested that COPRA-MOS could potentially apply for poultry industry as it exhibited beneficial effect on cecal fermentation and could be used as a decoy to prevent colonization of a pathogen while to increase the autoaggregation leading to adherence of a probiotic.

Caeca Microbial Variation in Broiler Chickens as a Result of Dietary Combinations Using Two Cereal Types, Supplementation of Crude Protein and Sodium Butyrate.

The intestinal microbiome can influence the efficiency and the health status of its host’s digestive system. Indigestible non-starch polysaccharides (NSP) serve as substrates for bacterial fermentation, resulting in short-chain fatty acids like butyrate. In broiler’s nutrition, dietary crude protein (CP) and butyrate’s presence is of particular interest for its impact on intestinal health and growth performance. In this study, we evaluated the effect on the microbial ecology of the ceca of dietary supplementations, varying the cereal type (maize and wheat), adequate levels of CP and supplementation of sodium butyrate on broiler chickens with 21 days. The overall structure of bacterial communities was statistically affected by cereal type, CP, and sodium butyrate (p = 0.001). Wheat in the diet promoted the presence of Lactobacillaceae, Bifidobacteriaceae and Bacteroides xylanisolvens, which can degrade complex carbohydrates. Maize positively affected the abundance of Bacteroides vulgatus. The addition of CP promoted the family Rikenellaceae, while sodium butyrate as feed supplement was positively related to the family Lachnospiraceae. Functional predictions showed an effect of the cereal type and a statistical significance across all supplementations and their corresponding interactions. The composition of diets affected the overall structure of broilers’ intestinal microbiota. The source of NSP as a substrate for bacterial fermentation had a stronger stimulus on bacterial communities than CP content or supplementation of butyrate.

Effects of Commercial Apple Varieties on Human Gut Microbiota Composition and Metabolic Output Using an In Vitro Colonic Model.

Apples are a rich source of polyphenols and fiber. A major proportion of apple polyphenols escape absorption in the small intestine and together with non-digestible polysaccharides reach the colon, where they can serve as substrates for bacterial fermentation. Animal studies suggest a synergistic interaction between apple polyphenols and the soluble fiber pectin; however, the effects of whole apples on human gut microbiota are less extensively studied. Three commercial apple varieties—Renetta Canada, Golden Delicious and Pink Lady—were digested and fermented in vitro using a batch culture colonic model (pH 5.5–6.0, 37 °C) inoculated with feces from three healthy donors. Inulin and cellulose were used as a readily and a poorly fermentable plant fiber, respectively. Fecal microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region) and Fluorescence in Situ Hybridization. Short chain fatty acids (SCFAs) and polyphenol microbial metabolites were determined. The three apple varieties significantly changed bacterial diversity, increased Actinobacteria relative abundance, acetate, propionate and total SCFAs (p < 0.05). Renetta Canada and Golden Delicious significantly decreased Bacteroidetes abundance and increased Proteobacteria proportion and bifidobacteria population (p < 0.05). Renetta Canada also increased Faecalibacterium prausnitzii, butyrate levels and polyphenol microbial metabolites (p < 0.05). Together, these data suggest that apples, particularly Renetta Canada, can induce substantial changes in microbiota composition and metabolic activity in vitro, which could be associated with potential benefits to human health. Human intervention studies are necessary to confirm these data and potential beneficial effects.

Potential use of scotta, the by-product of the ricotta cheese manufacturing process, for the production of fermented drinks.

In the present work, the use of scotta as substrate for bacterial fermentation was studied with the objective of obtaining a drink from transformation of this by-product. Scotta retains most of the lactose of the milk and it is normally colonized by a natural microbiota. A treatment was devised to reduce the autochthonous microbial populations in order to reduce competition towards the inoculated bacterial strains. Nine lactic acid bacteria (LAB) were assessed for their capability to develop in scotta. They evidenced different behaviors regarding growth rate, acidification capability and nitrogen consumption. A co-inoculum of three LAB, namely a Streptococcus thermophilus, a Lactobacillus delbrueckii subsp. bulgaricus and a Lb. acidophilus strains, chosen among those giving the best performances in single-strain fermentation trials, gave abundant (close to 10(9) cfu/ml) and balanced growth and lowered pH to 4.2, a value similar to that of yogurt. These results show that scotta may have potential as a substrate for bacterial growth for the production of a fermented drink. Further studies are needed to optimize the organoleptic aspects of the final product.

Probiotics and prebiotics in infant nutrition

The human colonic microflora has a central role in health and disease, being unique in its complexity and range of functions. As such, dietary modulation is important for improved gut health, especially during the highly-sensitive stage of infancy. Diet can affect the composition of the gut microflora through the availability of different substrates for bacterial fermentation. Differences in gut microflora composition and incidence of infection exist between breast-fed and formula-fed infants, with the former thought to have improved protection. Historically, this improvement has been believed to be a result of the higher presence of reportedly-beneficial genera such as the bifidobacteria. As such, functional food ingredients such as prebiotics and probiotics could effect a beneficial modification in the composition and activities of gut microflora of infants by increasing positive flora components. The prebiotic approach aims to increase resident bacteria that are considered to be beneficial for human health, e.g. bifidobacteria and lactobacilli, while probiotics advocates the use of the live micro-organisms themselves in the diet. Both approaches have found their way into infant formula feeds and aim to more closely simulate the gut microbiota composition seen during breast-feeding.

Substrate for fermentation in man

A variety of different substrates are excreted from the small bowel as possible substrates for bacterial fermentation in the large bowel. Ileostomy studies have shown that 50-90 g/d of dry weight (800-1700 kJ/d) is excreted from the small bowel. Although the amount of non-starch polysaccharides (NSP), the main component of dietary fibre in the diet, causes considerable changes in excretion patterns, NSP is not the dominant part of the energy excreted to the large bowel. Resistant starch in common Western diets amounts to 34% of the starch intake, if the diet is not high in e.g. beans. Oligosaccharides, sugars and fat contribute only a few grams each, whereas the excretion of protein can be estimated to 10-15 g/d. Calculation of substrate and energy shows that a considerable amount of energy, equivalent to 15-40 g of carbohydrate, is metabolised in the large bowel. Keywords: Bacteria, colon, energy, fermentation, nutrients