Background and Aims Crohn’s disease and ulcerative colitis evolve with alternate outbreaks and remissions of variable duration in both cases. Despite the advances, about 10-30% of patients do not respond to the treatment after the induction period. Besides, between 20% to 50% further patients need an optimization of the dose to respond the treatment. Recent studies have pointed gut microbiota can play a role in the anti-TNF treatment response. This study aimed to define a bacterial signature that could be used to predict the response of patients to anti-TNF treatment. Methods There were obtained 38 stool samples from 38 IBD patients before starting anti-TNF treatments: Adalimumab, Golimumab or Infliximab. Patients were differentiated in 2 groups: responders and non-responders to biological treatment. From each sample, DNA was purified and used in a qPCR for the quantification of the 8 microbial markers. Results In this proof of concept, the predictive ability to identify anti-TNF treatment responders was analyzed. An algorithm consisting in the combination of 4 bacterial markers showed a high capacity to discriminate between responders and non- responders. The algorithm proved high sensitivity and specificity reporting values of 93.33% and 100% respectively, with a positive predictive value of 100% and a negative predictive value of 75% for predicting response to biologic treatment. Conclusions A specific bacterial signature could beneficiate patients with inflammatory bowel disease predicting the therapeutic effectiveness of an anti-TNF treatment, leading to a personalized therapy, improving the patients’ quality of life, saving costs and gaining time in patient improvement.

Inflammatory bowel disease (IBD), including its two main categories (Crohn's disease and ulcerative colitis), has been linked both to gut microbiota and to diet. Bread is a daily food that has a potential capacity as a prebiotic. Our aim was to evaluate different bread-making processes and their effect on fecal colonic microbiota in IBD patients. The microbial composition of several sourdoughs and dough samples was analyzed by high-throughput sequencing of 16S and 18S rRNA genes. Three types of bread, which followed different bread-making processes, were in vitro digested and incubated with feces from IBD patients. Changes in gut microbiota were assessed by a quantitative polymerase chain reaction using specific bacterial sequence targets. Short-chain fatty acid production was also analyzed by gas chromatography. Lactobacillus sanfranciscensis was the dominant lactic acid bacteria species found in sourdough and bread doughs prepared using sourdough, whereas Saccharomyces cerevisiae was the most dominant yeast in all groups, especially in bread doughs before baking. Differences in microbial composition in raw bread doughs were more related to the type of dough and elaboration than to fermentation time lengths. The analysis of in vitro fecal incubations with bread conditions revealed an increase in most bacterial groups analyzed and short-chain fatty acid production, both in Crohn's disease and ulcerative colitis samples. Most remarkable increases in short-chain fatty acid production mirrored higher abundances of Roseburia species. The potential prebiotic properties observed were mainly obtained when using a high quantity of bread, regardless of bread type. Overall, this study highlights the bacterial dynamics within the bread-making process and the potential prebiotic effect in IBD patients.

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) patients have different faecal microbiota profiles compared to healthy controls. Prebiotics intake influences intestinal microbiota composition which in turn influence the growth of short-chain fatty acids (SCFA) producing bacteria. This study aimed to evaluate the capacity of Previpect, a new prebiotic obtained from grapes fibre, to balance the dysbiosis found in patients with intestinal disorders. This was achieved through the analysis of specific bacterial markers and SCFA production using an in vitro fermentation system and comparing the obtained results with those obtained with other commercial prebiotics. Fresh faecal samples from patients with IBD (N = 6), IBS (N = 3), and control subjects (N = 6) were used. Previpect showed high fermentative ability enabling the growth of butyrate producing bacteria and increasing SCFA concentration up to 2.5-fold. Previpect is a promising prebiotic which may be used as a therapeutic strategy towards promotion of intestinal microbiota restoration, microbial healing, and as a preventive supplement for healthy individuals.

Background Inflammatory Bowel Disease (IBD) is a clinical condition of the gastrointestinal tract of unknown aetiology. The two main forms of IBD are Crohn’s disease (CD) and Ulcerative colitis (UC). Recently, it has been reported that the bacterial communities present in the colon of patients with IBD are structurally different compared with those in healthy individuals. This particular dysbiosis consists of a decrease of butyrate producing bacteria and an increase of the pro-inflammatory species. The goal of this work was to test a new prebiotic of selected dietary fibre made from grape for its capacity to balance the dysbiosis typically found in patients with intestinal disorders. Methods Faecal samples from 16 healthy subjects and 11 IBD patients (5 CD and 6 UC) were collected by the Hospital Universitari Dr. Josep Trueta. Fresh stool samples were incubated with 200 mg, 600 mg of prebiotic, and 200 mg of apple pectin. A negative control without substrate addition was also performed. The tubes were incubated under continuous stirring for 72 hours at 37 ºC in semi-anaerobic atmosphere. Total DNA was extracted and the abundances of butyrate-producing bacterial markers (Faecalibacterium prausnitzii, and its phylogroups I and II, Roseburia hominis and Subdolinogranulum variabile) were analysed by qPCR. Concentrations of both butyrate and acetate were determined by gas chromatography as an indication of the bacterial metabolic activity. Results A significant increase of butyrate producing species, such as S. variabile, R. hominis and F. prausnitzii was observed in CD and UC samples when incubated with 200 mg of prebiotic compared with the negative control. F. prausnitzii phylogroup II, which is underrepresented in UC patients, also increased. No differences were found when samples were incubated with 600 mg. Regarding apple pectin, the increase on the abundance of butyrate producing bacteria was higher than the prebiotic in UC samples. In samples from healthy subjects, an increase in the butyrate producing species abundances was observed in both concentrations of prebiotic when compared with the negative control. In those samples no differences were observed when comparing apple pectin with the prebiotic. Concerning butyrate and acetate production, these substances increased in all prebiotic-supplemented samples when compared with the negative control. Conclusion The studied prebiotic causes an increase of the abundance and activity of butyrate-producing bacteria in both IBD patients and healthy subjects. These results points to this new dietary fibre as a promising prebiotic to maintain eubiosis and to promote the microbiota restoration of the intestinal mucosa.

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