The aim of this study was to monitor changes in the fecal microbiota from 9 to 18 months and to investigate the effect of increasing dietary n-3 polyunsaturated fatty acids on the fecal microbiota.
In a double-blind controlled trial with random allocation to daily supplementation with 5 mL of fish oil (FO) or sunflower oil (SO) from 9 to 18 months of age, stool samples were collected from 132 healthy Danish infants. Molecular fingerprints of the bacterial DNA were obtained by terminal restriction fragment length polymorphism (T-RFLP).
The T-RFLP profiles indicated that a few T-RFs became dominant with age (bp100 and 102, both presumed to be Bacteroidetes) concomitantly with an overall increase in the microbial diversity (P = 0.04). Breast-feeding influenced both the T-RFLP profiles at 9 months and the changes from 9 to 18 months, and breast-feeding cessation during the trial modified the response to the dietary oils. In the FO group, the increase in bp102 was significantly reduced among children weaned before compared with those weaned during the trial (P = 0.027), whereas the increase in bp100 was reduced in the preweaned children of the SO group relative to those weaned during the trial (P = 0.004). This was supported by intervention group differences in the changes in bp102 and bp100 among the earlier weaned children (P = 0.06 and P = 0.09, respectively).
Cessation of breast-feeding played a dominant role relative to developmental changes in the fecal microbiota from 9 to 18 months. FO compared with SO supplementation affected changes in large bacterial groups, but only among children who had stopped breast-feeding before 9 months of age.
"However, there is limited evidence on the association between dietary fatty acid profiles and intestinal bacterial composition. Andersen et al. (2011) reported that fish oil as opposed to sunflower oil affected the intestinal bacterial profile of infants who discontinued breastfeeding before nine months of age. Intestinal bacterial profiles of Mus musculus are influenced by the saturation level of dietary fatty acids (Liu et al., 2012), and fish oil treatment caused significant changes in the intestinal microbiota of mice based on PCR–DGGE profiling (Yu et al., 2014). "
[Show abstract][Hide abstract] ABSTRACT: Even though the Pacific white shrimp is a very important culture species, there is little information on the effect of feed nutrients on the intestinal microbiota. In shrimp, dietary fatty acids largely affect the growth and immune system of Litopenaeus vannamei in part by changing the intestinal bacterial profile. Therefore, an Illumina-based sequencing method was used to examine the intestinal bacterial composition of L. vannamei following six diets with different lipid sources. The bacterial communities in the culture water and shrimp intestinal contents were also compared. The results revealed that shrimp fed a diet with an equal combination of soybean oil, beef tallow, and linseed oil (SBL) had significantly higher weight gain and survival rate than those fed with soybean oil or beef tallow. Proteobacteria and Tenericutes were dominant in the intestines of L. vannamei regardless of the diet. There was a significant prevalence of Rhizobiaceae in shrimp fed the SBL diet than in shrimp fed diets with soybean oil or beef tallow. Proteobacteria dominated in both the culture water and shrimp intestinal samples of L. vannamei. These results suggest that the host intestinal environment imposes selective pressure on the establishment of microbial communities. Lipid sources with different fatty acid compositions could affect the composition of the intestinal microbiota of L. vannamei.
"The diversity index was calculated as described previously
. In brief, the Shannon-Weaver index of diversity (H’) based on all of the initial T-RFs was used to determine the diversity of the bacterial fragments. "
[Show abstract][Hide abstract] ABSTRACT: Background
Obesity induced by a high-caloric diet has previously been associated with changes in the gut microbiota in mice and in humans. In this study, pigs were cloned to minimize genetic and biological variation among the animals with the aim of developing a controlled metabolomic model suitable for a diet-intervention study. Cloning of pigs may be an attractive way to reduce genetic influences when investigating the effect of diet and obesity on different physiological sites. The aim of this study was to assess and compare the changes in the composition of the gut microbiota of cloned vs. non-cloned pigs during development of obesity by a high-fat/high-caloric diet. Furthermore, we investigated the association between diet-induced obesity and the relative abundance of the phyla Firmicutes and Bacteroidetes in the fecal-microbiota. The fecal microbiota from obese cloned (n = 5) and non-cloned control pigs (n= 6) was investigated biweekly over a period of 136 days, by terminal restriction fragment length polymorphism (T-RFLP) and quantitative real time PCR (qPCR).
A positive correlation was observed between body-weight at endpoint and percent body-fat in cloned (r=0.9, P<0.0001) and in non-cloned control pigs (r=0.9, P<0.0001). Shannon Weaver and principal component analysis (PCA) of the terminal restriction fragments (T-RFs) revealed no differences in the bacterial composition or variability of the fecal microbiota between the cloned pigs or between cloned and non-cloned control pigs. Body-weight correlated positively with the relative abundance of Firmicutes in both cloned (r=0.37; P<0.02) and non cloned-control pigs (r=0.45; P<0.006), and negatively with the abundance of Bacteroidetes in cloned pigs (r=−0.33, P<0.04), but not in the non-cloned control pigs.
The cloned pigs did not have reduced inter-individual variation as compared to non-cloned pigs in regard to their gut microbiota in neither the obese nor the lean state. Diet-induced obesity was associated with an increase in the relative abundance of Firmicutes over time. Our results suggest that cloned pigs are not a more suitable animal model for gut microbiota-obesity related studies than non-cloned pigs. This study is the first to evaluate if cloned pigs provide a better animal model than conventional pigs in diet-intervention, obesity and gut microbiota research.
[Show abstract][Hide abstract] ABSTRACT: Many dietary fatty acids (FA) have potent effects on inflammation, which is not only energetically costly, but also contributes to a range of chronic diseases. This presents an evolutionary paradox: Why should the host initiate a costly and damaging response to commonly encountered nutrients? We propose that the immune system has evolved a capacity to modify expenditure on inflammation to compensate for the effects of dietary FA on gut microorganisms. In a comprehensive literature review, we show that the body preferentially upregulates inflammation in response to saturated FA that promote harmful microbes. In contrast, the host opften reduces inflammation in response to the many unsaturated FA with antimicrobial properties. Our model is supported by contrasts involving shorter-chain FA and omega-3 FA, but with less consistent evidence for trans fats, which are a recent addition to the human diet. Our findings support the idea that the vertebrate immune system has evolved a capacity to detect diet-driven shipfts in the composition of gut microbiota from the profile of FA consumed and to calibrate the costs of inflammation in response to these cues. We conclude by extending the nutrient signaling model to other nutrients, and consider implications for drug discovery and public health.
The Quarterly Review of Biology 09/2012; 87(3):187-223. DOI:10.1086/666828 · 4.89 Impact Factor
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