Skate-Skin Mucin, Rich in Sulfated Sugars and Threonine, Promotes Proliferation of Akkermansia muciniphila in Feeding Tests in Rats and In Vitro Fermentation Using Human Feces

Dietary factors, affect Akkermansia muciniphila (AM) abundance in the colon, have attracted attention, driven by the inverse correlation between AM abundance and metabolic disorders. We prepared skate-skin mucin (SM), porcine stomach mucin (PM), and rat gastrointestinal mucin (RM). SM contained more sulfated sugars and threonine than PM or RM. Rats were fed a control diet or diets including SM, PM, or RM (15 g/kg), or SM (12 g/kg) from five different threonine contents for 14 d. Cecal total bacteria and AM were less and more numerous, respectively, in SM-fed rats than the others, but SM did not affect microbial species-richness. Low-threonine SM did not induce AM proliferation. The in vitro fermentation with human feces showed that the rate of AM increase was greater with SM than PM. Collectively, heavy SM sulfation facilitates a priority supply of SM-derived amino sugars and threonine that promotes AM proliferation in rats and human feces.

Potential of phenolic compounds and their gut microbiota-derived metabolites to reduce microbial TMA formation: Application of an in vitro fermentation high throughput screening model

Trimethylamine N-oxide (TMAO) is a pro-atherosclerotic product of dietary choline metabolism generated by a microbiome-host axis. The first step in this pathway is enzymatic metabolism of choline to trimethylamine (TMA) by the gut microbiota. This reaction could be targeted to reduce atherosclerosis risk. We aimed to evaluate potential inhibitory effects of select dietary phenolics and their relevant gut microbial metabolites on TMA production via a human ex vivo-in vitro fermentation model. Various phenolics inhibited choline use and TMA production. The most bioactive compounds tested (caffeic acid, catechin and epicatechin) reduced TMA-d9 formation (compared to control) by 57.5 ± 1.3% to 72.5 ± 0.4% at 8 h and preserved remaining choline-d9 concentrations by 194.1 ± 6.4% to 256.1 ± 6.3% compared to control conditions at 8 h. These inhibitory effects were achieved without altering cell respiration or cell growth. However, inhibitory effects decreased at late fermentation times, which suggest that these compounds delay choline metabolism rather than completely inhibiting TMA formation. Overall, caffeic acid, catechin and epicatechin were the most effective non-cytotoxic inhibitors of choline use and TMA production. Thus, these compounds are proposed as lead bioactives to test in vivo.

Effect of addition cattle feed supplement on in vitro fermentation, synthesis of microbial biomass, and methane production of rice straw fermentation basal diets

The objective of this study was to evaluate the influence of supplementation of cattle feed supplement (CFS) and concentrate in ruminant diets based on rice straw fermented (R) on in vitro rumen fermentation, microbial biomass synthesis, and enteric methane production. Five experimental diets were evaluated, consist of R = rice straw fermented 100%, RS = R + CFS 10%, RSC1, 2 and 3 = RS + Concentrate levels 10, 20 and 30 (%DM). Supplementation of CFS increased the gas production (P < 0.05) and highest in treatments RSC1 and 2 (44.09 and 44.87 ml/g substrate, respectively) and was decreased proportions of methane by inhibition rate until 49.80%. Ruminal protozoa population increased by CFS dan concentrate supplementation (P<0,05) and was dominated (>80%) of Entodinium genus. The treatments RS dan RSC1 promoted greater (P < 0.01) microbial biomass synthesis (386.32 and 312.39 mg/g substrate, respectively). In conclusion, the supplementation of CFS and concentrate in ruminant diets based on rice straw fermented can promote a greater synthesis of microbial biomass and mitigation of methane production.

Potential of phenolic compounds and their gut microbiota-derived metabolites to reduce microbial TMA formation: Application of an in vitro fermentation high throughput screening model

Trimethylamine N-oxide (TMAO) is a pro-atherosclerotic product of dietary choline metabolism generated by a microbiome-host axis. The first step in this pathway is enzymatic metabolism of choline to trimethylamine (TMA) by the gut microbiota. This reaction could be targeted to reduce atherosclerosis risk. We aimed to evaluate potential inhibitory effects of select dietary phenolics and their relevant gut microbial metabolites on TMA production via a human ex vivo-in vitro fermentation model. Various phenolics inhibited choline use and TMA production, especially larger compounds or their larger metabolites, without altering cell respiration or cell growth. However, inhibitory effects decreased at late fermentation times, which suggest that these compounds delay choline metabolism rather than completely inhibiting TMA formation. Overall, caffeic acid, catechin and epicatechin were the most effective non-cytotoxic inhibitors of choline use and TMA production. Thus, these compounds are proposed as lead bioactives to test in vivo.

The addition of feed additive in beef cattle ration on in vitro fermentation characteristics

The effects of feed additives are increasing feed digestibility, balance of rumen microbial community, stimulating the immune response and livestock productivity. This study aimed to determine the effects of feed additives combination in the rumen fermentation. The method used in this study was a block randomized design with 9 treatments and 3 replications. The experiment using Theodorou In vitro method for 48 hours with parameters such as pH, kinetics gas and methane production, DMD, OMD, NH3, and partial VFA. The treatment were P0; control (Basal Diet 70% Concentrate + 30% Forages), P1; P0 + Premix, P2; P1 + Probiotic, P3; P1 + Enzyme, P4; P1 + Plant Extract, P5; P1 + (Probiotics + Enzyme), P6; P1 + (Probiotics + Plant Extract), P7; P1 + (Probiotic + Enzyme + Plant Extract), and P8; P1 + (Enzyme + Plant Extract). The results showed kinetics gas, methane production, NH3, and partial VFA were significantly affected (P <0.05), while the value of pH, DMD, and OMD was not significant. In conclusion, the addition of mix feed additives can affect the kinetics gas and methane production. However, it does not affect the level of pH, dry matter and organic matter digestibility.

Influence of Human Age on the Prebiotic Effect of Pectin-Derived Oligosaccharides Obtained from Apple Pomace

The aim of this study was to evaluate the prebiotic effect of pectin-derived oligosaccharides (POS) obtained from apple pomace on the growth and metabolism of microbiota from the human gastrointestinal tract as a function of the age of the host. The counts of major bacterial groups Bifidobacterium sp., lactobacilli, Clostridium sp., Bacteroides sp., Enterococcus sp. and Enterobacteria were assessed during long-term in vitro fermentation of mixed cultures in a prebiotic medium. Comparative assessment of bacterial diversity in the human fecal microbiota was performed relative to the age of the host, from childhood to old age, through younger years and middle age. The age group of the host was found to be an important factor that determined the prebiotic effect of POS, which was related to both the qualitative and quantitative composition of fecal microbiota and its metabolism. In contrast to the microbiota of elderly subjects, the child-derived intestinal microbiota underwent significantly different alterations in terms of the proportion and composition of lactic acid bacteria, leading to a more favorable pattern of short-chain fatty acids (SCFA) and lactic acid levels.

332 Effect of Chemical and Biological Preservatives on in vitro Fermentation and Methane Production of Ensiled and Aerobically Exposed Wet Brewer’s Grains

This study evaluated the effects of preservatives on the in vitro fermentation measures of wet brewer’s grain (WBG) silage at different stages of storage. Treatments (TRT) were sodium lignosulfonate at 1% (NaL1) and 2% (NaL2; w/w of fresh WBG), propionic acid (PRP; 0.5% w/w of fresh WBG), a combination inoculant (INO; Lactococcus lactis and Lactobacillus buchneri each at 4.9 log cfu/fresh WBG g), and untreated WBG (CON). WBG (Fresh) were packed into 8.8 L mini-silos and stored for 60 d at 21°C (Ensiled), then they were opened and aerobically exposed for 10d (AES). Samples from each stage of storage (STG; Fresh, Ensiled and AES) were analyzed for in vitro ruminal digestibility (24 h).Gas kinetics were recorded using the Ankom RF Gas Production System. Data were analyzed as a randomized complete block design (5 blocks) with a 5 (TRT) × 3 (STG) factorial arrangement. Apparent in vitro DM digestibility (DMD) decreased across STG, (51.5, 47.2 and 40.9 for Fresh, Ensiled and AES, respectively) and increased for NaL1, NaL2 and PRP (~47.8) vs. CON (43.0 ± 2.12%). PRP increased apparent in vitro OM digestibility (OMD) when Ensiled (54.5) and NaL2 increased it for AES (47.1) vs CON (46.3 and 39.9 ± 1.73%, respectively). The asymptotic maximal (M) and rate (k) of gas production decreased across STG (214.6, 181.5, 155.1 and 14.6, 12.6, and 9.8, for Fresh, Ensiled and AES, respectively). PRP increased (200.0) and NaL1 decreased (169.3) M vs. CON (183.9± 7.81ml/incubated DM g), while NaL1 and NaL2 (~11.4) decreased k vs. CON (13.4 ± 0.85%/h). Methane concentration and yield were higher in Fresh vs. other STG (0.94 vs. ~0.84 ± 0.07mM and 0.27 vs. ~0.23 ± 0.03mmol/g fermented OM). Spoilage of WBG decreases fermentability and methane production while PRP and NaL improve digestibility with the former also increasing M and k.