***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective To highlight the contribution of the gut microbiota to the modulation of host metabolism by dietary inulin-type fructans ( ITF prebiotics ) in obese women . Methods A double blind , placebo controlled , intervention study was performed with 30 obese women treated with ITF prebiotics ( inulin/oligofructose 50/50 mix ; n=15 ) or placebo ( maltodextrin ; n=15 ) for 3 months ( 16 g/day ) .  Blood , faeces and urine sampling , oral glucose tolerance test , homeostasis model assessment and impedancemetry were performed before and after treatment . The gut microbial composition in faeces was analysed by phylogenetic microarray and qPCR analysis of 16S rDNA . Plasma and urine metabolic profiles were analysed by 1H-NMR spectroscopy . Results Treatment with ITF prebiotics , but not the placebo , led to an increase in Bifidobacterium and Faecalibacterium prausnitzii ; both bacteria negatively correlated with serum lipopolysaccharide levels .  ITF prebiotics also decreased Bacteroides intestinalis , Bacteroides vulgatus and Propionibacterium , an effect associated with a slight decrease in fat mass and with plasma lactate and phosphatidylcholine levels . No clear treatment clustering could be detected for gut microbial analysis or plasma and urine metabolomic profile analyses . However , ITF prebiotics led to subtle changes in the gut microbiota that may importantly impact on several key metabolites implicated in obesity and /or diabetes . Conclusions ITF prebiotics selectively changed the gut microbiota composition in obese women , leading to modest changes in host metabolism , as suggested by the correlation between some bacterial species and metabolic endotoxaemia or metabolomic signatures Background The fermentation of dietary fiber to various organic acids is a beneficial function provided by the microbiota in the human large intestine . In particular , butyric acid contributes to host health by facilitating maintenance of epithelial integrity , regulating inflammation , and influencing gene expression in colonocytes . We sought to increase the concentration of butyrate in 20 healthy young adults through dietary supplementation with resistant starch ( unmodified potato starch — resistant starch ( RS ) type 2 ) . Methods Fecal sample s were collected from individuals to characterize butyrate concentration via liquid chromatography and composition of the microbiota via surveys of 16S rRNA-encoding gene sequences from the Illumina MiSeq platform . R and om Forest and LEfSe analyses were used to associate responses in butyrate production to features of the microbiota . Results RS supplementation increased fecal butyrate concentrations in this cohort from 8 to 12 mmol/kg wet feces , but responses varied widely between individuals . Individuals could be categorized into three groups based upon butyrate concentrations before and during RS : enhanced , high , and low ( n = 11 , 3 , and 6 , respectively ) . Fecal butyrate increased by 67 % in the enhanced group ( from 9 to 15 mmol/kg ) , while it remained ≥11 mmol/kg in the high group and ≤8 mmol/kg in the low group . Microbiota analyses revealed that the relative abundance of RS-degrading organisms — Bifidobacterium adolescentis or Ruminococcus bromii — increased from ~2 to 9 % in the enhanced and high groups , but remained at ~1.5 % in the low group . The lack of increase in RS-degrading bacteria in the low group may explain why there was no increase in fecal butyrate in response to RS . The microbiota of individuals in the high group were characterized by an elevated abundance of the butyrogenic microbe Eubacterium rectale ( ~6 % in high vs. 3 % in enhanced and low groups ) throughout the study . Conclusions We document the heterogeneous responses in butyrate concentrations  upon RS supplementation and identify characteristic of the microbiota that appear to underlie this variation . This study complements and extends other studies that call for personalized approaches to manage beneficial functions provided by gut microbiomes Background Roux-en-Y gastric bypass ( RYGB ) is an effective means to achieve sustained weight loss for morbidly obese individuals . Besides rapid weight reduction , patients achieve major improvements of insulin sensitivity and glucose homeostasis . Dysbiosis of gut microbiota has been associated with obesity and some of its co-morbidities , like type 2 diabetes , and major changes of gut microbial communities have been hypothesized to mediate part of the beneficial metabolic effects observed after RYGB . Here we describe changes in gut microbial taxonomic composition and functional potential following RYGB . Methods We recruited 13 morbidly obese patients who underwent RYGB  , carefully phenotyped them , and had their gut microbiomes quantified before ( n = 13 ) and 3 months ( n = 12 ) and 12 months ( n = 8) after RYGB . Following shotgun metagenomic sequencing of the fecal microbial DNA purified from stools , we characterized the gut microbial composition at species and gene levels followed by functional annotation . Results In parallel with the weight loss and metabolic improvements , gut microbial diversity increased within the first 3 months after RYGB and remained high 1 year later . RYGB led to altered relative abundances of 31 species ( P < 0.05 , q < 0.15 ) within the first 3 months , including those of Escherichia coli , Klebsiella pneumoniae , Veillonella spp . , Streptococcus spp . , Alistipes spp . , and Akkermansia muciniphila . Sixteen of these species maintained their altered relative abundances during the following 9 months . Interestingly , Faecalibacterium prausnitzii was the only species that decreased in relative abundance . Fifty-three microbial functional modules increased their relative abundance between baseline and 3 months ( P < 0.05 , q < 0.17 ) . These functional changes included increased potential ( i ) to assimilate multiple energy sources using transporters and phosphotransferase systems , ( ii ) to use aerobic respiration , ( iii ) to shift from protein degradation to putrefaction , and ( iv ) to use amino acids and fatty acids as energy sources . Conclusions Within 3 months after morbidly obese individuals had undergone RYGB , their gut microbiota featured an increased diversity , an altered composition , an increased potential for oxygen tolerance , and an increased potential for microbial utilization of macro- and micro-nutrients . These changes were maintained for the first year post-RYGB.Trial registration Current controlled trials ( ID NCT00810823 , NCT01579981 , and NCT01993511 ) Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The clinical study reported here was conducted in order to analyze the anti-obesity effect of the steamed root of Rehmannia glutinosa Libosch ( Shu Dihuang ) , a Chinese herbal medicine widely used for the treatment of metabolic diseases . To underst and the mechanism(s ) underlying the beneficial effects of R. glutinosa , we investigated the changes in gut microbiota after herbal intervention through 16S rRNA gene-based pyrosequencing analyses . Twelve female middle-aged subjects ( 40 - 65 years old ) with body mass index ( BMI ) over 25 kg m(-2 ) were included in this study which involved intake of steamed roots of R. glutinosa for eight weeks . The subjects were visited for anthropometric measurements every two weeks and fecal sample s were collected before and after the intervention . All subjects showed a significantly decreased waist circumference following the herbal treatment . The relative abundances of fecal microbiota suggested an association of intake of R. glutinosa with increases in phylum Actinobacteria and genus Bifidobacterium , while phylum Firmicutes and genus Blautia were decreased in response to the herbal treatment . Based on these findings , it is conceivable that a decrease in the waist circumferences after R. glutinosa intake may be related to alteration of intestinal microbiota and the herbal intervention has the potential as a prebiotic Summary Bariatric surgery is currently the most effective procedure for the treatment of obesity . Given the role of the gut microbiota in regulating host metabolism and adiposity , we investigated the long-term effects of bariatric surgery on the microbiome of patients r and omized to Roux-en-Y gastric bypass or vertical b and ed gastroplasty and matched for weight and fat mass loss . The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and result ed in altered levels of fecal and circulating metabolites compared with obese controls . By colonizing germ-free mice with stools from the patients , we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice . These mice also had a lower respiratory quotient , indicating decreased utilization of carbohydrates as fuel . Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery The gut microbiota exerts a role in type 2 diabetes ( T2D ) , and deviations from a mutualistic ecosystem layout are considered a key environmental factor contributing to the disease . Thus , the possibility of improving metabolic control in T2D by correcting gut microbiome dysbioses through diet has been evaluated . Here , we explore the potential of two different energy-restricted dietary approaches – the fibre-rich macrobiotic Ma-Pi 2 diet or a control diet recommended by Italian professional societies for T2D treatment – to correct gut microbiota dysbioses in T2D patients . In a previous 21-d open-label MADIAB trial , fifty-six overweight T2D patients were r and omised to the Ma-Pi 2 or the control diet . For the present study , stools were collected before and after intervention from a subset of forty MADIAB participants , allowing us to characterise the gut microbiota by 16S rRNA sequencing and imputed metagenomics . To highlight microbiota dysbioses in T2D , the gut microbiota of thirteen normal-weight healthy controls were characterised . According to our findings , both diets were effective in modulating gut microbiome dysbioses in T2D , result ing in an increase of the ecosystem diversity and supporting the recovery of a balanced community of health-promoting SCFA producers , such as Faecalibacterium , Roseburia , Lachnospira , Bacteroides and Akkermansia .  The Ma-Pi 2 diet , but not the control diet , was also effective in counteracting the increase of possible pro-inflammatory groups , such as Collinsella and Streptococcus , in the gut ecosystem , showing the potential to reverse pro-inflammatory dysbioses in T2D , and possibly explaining the greater efficacy in improving the metabolic control Background Gut lactobacilli can affect the metabolic functions of healthy humans . We tested whether a 1500 kcal/d diet supplemented with cheese containing the probiotic Lactobacillus plantarum TENSIA ( Deutsche Sammlung für Mikroorganismen , DSM 21380 ) could reduce some symptoms of metabolic syndrome in Russian adults with obesity and hypertension . Methods In this 3-week , r and omized , double-blind , placebo-controlled , parallel pilot study , 25 subjects ingested probiotic cheese and 15 ingested control cheese .  Fifty grams of each cheese provided 175 kcal of energy . Blood pressure ( BP ) , anthropometric characteristics , markers of liver and kidney function , metabolic indices ( plasma glucose , lipids , and cholesterol ) , and urine polyamines were measured . Counts of fecal lactobacilli and L. plantarum TENSIA were evaluated using molecular methods . The data were analyzed by t-test for independent sample s and Spearman ’s partial correlation analysis . Results The probiotic L. plantarum TENSIA was present in variable amounts ( 529.6 ± 232.5 gene copies ) in 16/25 ( 64 % ) study subjects . Body mass index ( BMI ) was significantly reduced ( p = 0.031 ) in the probiotic cheese group versus the control cheese group . The changes in BMI were closely associated with the water content of the body ( r = 0.570 , p = 0.0007 ) when adjusted for sex and age . Higher values of intestinal lactobacilli after probiotic cheese consumption were associated with higher BMI ( r = 0.383 , p = 0.0305 ) and urinary putrescine content ( r = 0.475 , p = 0.006 ) . In patients simultaneously treated with BP-lowering drugs , similar reductions of BP were observed in both groups . A positive association was detected between TENSIA colonization and the extent of change of morning diastolic BP ( r = 0.617 , p = 0.0248 ) and a trend toward lower values of morning systolic BP ( r = −0.527 , p = 0.0640 ) at the end of the study after adjusting for BMI , age , and sex . Conclusion In a pilot study of obese hypertensive patients , a hypocaloric diet supplemented with a probiotic cheese helps to reduce BMI and arterial BP values , recognized symptoms of metabol 
    Output:
    
Restrictive diets decreased the microbiota abundance , correlated with nutrient deficiency rather than weight loss and generally reduced the butyrate producers Firmicutes , Lactobacillus sp. and Bifidobacterium sp. The impact of surgical intervention depended on the given technique and showed a similar effect on butyrate producers , in addition to increasing the presence of the Proteobacteria phylum , which is related to changes in the intestinal absorptive surface , pH and digestion time .
Probiotics differed in strain and duration with diverse effects on the microbiota , and they tended to reduce body fat .
Prebiotics had a bifidogenic effect and increased butyrate producers , likely due to cross-feeding interactions , contributing to the gut barrier and improving metabolic outcomes .
All of the interventions under consideration had impacts on the gut microbiota , although they did not always correlate with weight loss .
These results show that restrictive diets and bariatric surgery reduce microbial abundance and promote changes in microbial composition that could have long-term detrimental effects on the colon .
In contrast , prebiotics might restore a healthy microbiome and reduce body fat