Fecal bacterial microbiota in constipated patients before and after eight weeks of daily Bifidobacterium infantis 35624 administration.

INTRODUCTION AND AIM: In recent years, probiotics have been used in functional gastrointestinal disorders, including chronic constipation (CC). The effect of Bifidobacterium infantis strain 35624 on the gut microbiota of CC patients has not been previously studied. Our aim was to analyze the fecal microbiota of constipated patients, before and after consuming a single-strain probiotic (B. infantis strain 35624). MATERIALS AND METHODS: We used 16S rRNA gene high-throughput sequencing to analyze the fecal microbiota of female patients (n=13) with CC. Patients were instructed to ingest one capsule of Alflorex® (containing 1×109 CFUs/g B. infantis strain 35624) daily for eight weeks. Fecal samples were obtained at the baseline and end (final) of probiotic administration. RESULTS: Alpha diversity metrics did not differ between the baseline and final periods. The butyrate producer, Oscillospira, was the taxon most strongly correlated with amplicon sequence variants (R2=0.55, p<0.0001). Except for a few bacterial taxa, there were no significant differences in relative abundance between the baseline and final periods. Beta-diversity measures also showed limited evidence for the differences between the two time periods. CONCLUSIONS: The results suggest that the fecal bacterial microbiota remains stable in constipated women consuming a single-strain probiotic. Those findings may be helpful in better understanding probiotic functioning in patients with digestive disorders.

Differential analysis of the bacterial community in colostrum samples from women with gestational diabetes mellitus and obesity.

Gestational Diabetes Mellitus (GDM) and obesity affect the functioning of multiple maternal systems and influence colonization of the newborn gastrointestinal through the breastmilk microbiota (BMM). It is currently unclear how GDM and obesity affect the human BMM composition. Here, we applied 16S-rRNA high-throughput sequencing to human colostrum milk to characterize BMM taxonomic changes in a cohort of 43 individuals classified in six subgroups according to mothers patho-physiological conditions (healthy control (n = 18), GDM (n = 13), or obesity (n = 12)) and newborn gender. Using various diversity indicators, including Shannon/Faith phylogenetic index and UniFrac/robust Aitchison distances, we evidenced that BMM composition was influenced by the infant gender in the obesity subgroup. In addition, the GDM group presented higher microbial diversity compared to the control group. Staphylococcus, Corynebacterium 1, Anaerococcus and Prevotella were overrepresented in colostrum from women with either obesity or GDM, compared to control samples. Finally, Rhodobacteraceae was distinct for GDM and 5 families (Bdellovibrionaceae, Halomonadaceae, Shewanellaceae, Saccharimonadales and Vibrionaceae) were distinct for obesity subgroups with an absolute effect size greater than 1 and a q-value ≤ 0.05. This study represents the first effort to describe the impact of maternal GDM and obesity on BMM.

Review: Are there indigenous Saccharomyces in the digestive tract of livestock animal species? Implications for health, nutrition and productivity traits.

All livestock animal species harbour complex microbial communities throughout their digestive tract that support vital biochemical processes, thus sustaining health and productivity. In part as a consequence of the strong and ancient alliance between the host and its associated microbes, the gut microbiota is also closely related to productivity traits such as feed efficiency. This phenomenon can help researchers and producers develop new and more effective microbiome-based interventions using probiotics, also known as direct-fed microbials (DFMs), in Animal Science. Here, we focus on one type of such beneficial microorganisms, the yeast Saccharomyces. Saccharomyces is one of the most widely used microorganisms as a DFM in livestock operations. Numerous studies have investigated the effects of dietary supplementation with different species, strains and doses of Saccharomyces (mostly Saccharomyces cerevisiae) on gut microbial ecology, health, nutrition and productivity traits of several livestock species. However, the possible existence of Saccharomyces which are indigenous to the animals' digestive tract has received little attention and has never been the subject of a review. We for the first time provide a comprehensive review, with the objective of shedding light into the possible existence of indigenous Saccharomyces of the digestive tract of livestock. Saccharomyces cerevisiae is a nomadic yeast able to survive in a broad range of environments including soil, grass and silages. Therefore, it is very likely that cattle and other animals have been in direct contact with this and other types of Saccharomyces throughout their entire existence. However, to date, the majority of animal scientists seem to agree that the presence of Saccharomyces in any section of the gut only reflects dietary contamination; in other words, these are foreign organisms that are only transiently present in the gut. Importantly, this belief (i.e. that Saccharomyces come solely from the diet) is often not well grounded and does not necessarily hold for all the many other groups of microbes in the gut. In addition to summarizing the current body of literature involving Saccharomyces in the digestive tract, we discuss whether the beneficial effects associated with the consumption of Saccharomyces may be related to its foreign origin, though this concept may not necessarily satisfy the theories that have been proposed to explain probiotic efficacy in vivo. This novel review may prove useful for biomedical scientists and others wishing to improve health and productivity using Saccharomyces and other beneficial microorganisms.

The health enhancer yeast Saccharomyces cerevisiae in two types of commercial products for animal nutrition.

The health enhancer yeast Saccharomyces cerevisiae (SC) is widely used in diets for different animals. Two main types of SC-based products are commercially available, one containing live yeasts and one containing SC fermentation by-products, which are supposedly not dependent on live yeasts for their physiological effects in vivo. Culture-based techniques were applied to study yeasts in two types of commercial products: a product containing live SC (LSC) and a SC fermentation product (SCFP). Three temperatures (25, 30 and 39°C) and two pH levels (4 and 7) were tested. The product with LSC contained an average of 1·21 × 109 colony-forming units (CFUs) of yeasts per g contents (min: 1 × 108 , max: 3 × 109 ). In contrast, the SCFP contained an average of 4·67 × 103 (min: 3 × 102 , max: 1·9 × 104 ) CFUs per g contents (c. 1 million times less than the concentration of yeasts in the product with LSC). Both temperature and pH level affected the number of CFUs but this effect differed between the two products. Biochemical tests identified the two yeasts as SC, which differed in their ability to ferment maltose (negative in the SCFP). This report encourages more research on commercial microbial strains for animal nutrition that can lead to a better understanding of their mode of action in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: Probiotics (or direct fed microbials) are increasingly popular in Animal Nutrition. Different products containing live micro-organisms or microbial-derived products are commercially available to enhance health and boost commercial traits. The characteristics of these products dictate their physiological effects and determine their potential to increase profitability from livestock. For the first time, this report presents data about the numbers and phenotype of the health enhancer Saccharomyces cerevisiae in two widely available commercial products in Animal Nutrition. These findings may be useful for scientists and producers around the globe and have the potential to open up novel venues for research.