Increasing adherence to the Mediterranean diet and lifestyle is associated with reduced fecal calprotectin and intra-individual changes in microbial composition of healthy subjects.

The Mediterranean diet (MED) is associated with the modification of gut microbial composition. In this pilot study, we investigate the feasibility of a microbiota-targeted MED-based lifestyle intervention in healthy subjects. MED intervention integrating dietary counseling, a supporting mobile application, and daily physical activity measurement using step trackers was prospectively applied for 4 weeks. Blood and fecal samples were collected at baseline, after the 4-week intervention, and at 6 and 12 months. Blood counts, inflammatory markers, microbial and eukaryotic composition were analyzed. Dietary adherence was assessed using daily questionnaires. All 20 healthy participants (females 65%, median age 37), completed the 4-week intervention. Adherence to MED increased from 15.6 ± 4.1 (baseline) to 23.2 ± 3.6 points (4 weeks), p < .01, reflected by increased dietary fiber and decreased saturated fat intake (both p < .05). MED intervention modestly reduced fecal calprotectin, white blood cell, neutrophil, and lymphocyte counts, within the normal ranges (P < .05). Levels of butyrate producers including Faecalibacterium and Lachnospira were positively correlated with adherence to MED and the number of daily steps. Bacterial composition was associated with plant-based food intake, while fungal composition with animal-based food as well as olive oil and sweets. Increasing adherence to MED correlated with increased absolute abundances of multiple beneficial gut symbionts. Therefore, increasing adherence to MED is associated with reduction of fecal calprotectin and beneficial microbial alterations in healthy subjects. Microbiota targeted lifestyle interventions may be used to modify the intestinal ecosystem with potential implications for microbiome-mediated diseases.

Adherence to the Mediterranean diet is associated with decreased fecal calprotectin in patients with ulcerative colitis after pouch surgery.

BACKGROUND: Mediterranean diet (MED) is associated with health benefits, yet scarce data exist regarding the role of MED in inflammatory bowel diseases (IBD). Herein, we aimed to evaluate the association between MED and inflammatory markers in patients with IBD after pouch surgery. METHODS: Consecutive patients after pouch surgery due to ulcerative colitis (UC) were recruited at a comprehensive pouch clinic. Adherence to MED was calculated according to MED score, ranging from 0 (low adherence) to 9 (high adherence), based on food-frequency questionnaires. Pouch behavior was defined as normal pouch (NP) or pouchitis based on Pouchitis Disease Activity Index (PDAI) and disease activity was defined as active or inactive. C-reactive protein (CRP) and fecal calprotectin were assessed. RESULTS: Overall 153 patients were enrolled (male gender 47%; mean age 46 ± 14 years; mean pouch age 9.5 ± 7 years). MED scores were higher in patients with normal vs. elevated CRP and calprotectin levels (4.6 ± 1.8 vs. 4.4 ± 1.6, p = 0.28; 4.8 ± 1.8 vs. 4.07 ± 1.7, p < 0.05, respectively). In a multivariate regression, MED score was associated with decreased calprotectin levels (OR = 0.74 [0.56-0.99]). Adherence to MED was associated with dietary fiber and antioxidants intake. Finally, in a subgroup of patients with NP followed up for 8 years, higher adherence to MED trended to be inversely associated with the onset of pouchitis (log rank = 0.17). CONCLUSIONS: In patients with UC after pouch surgery, adherence to MED is associated with decreased calprotectin levels. Thus, MED may have a role in modifying intestinal inflammation in IBD.

Fruit Consumption is Associated with Alterations in Microbial Composition and Lower Rates of Pouchitis.

BACKGROUND: Patients with ulcerative colitis [UC] who undergo proctocolectomy with an ileal pouch-anal anastomosis commonly develop pouch inflammation [pouchitis]. Pouchitis develops in a previously normal small intestine and may involve environmental factors. We explored whether diet and microbiota alterations contributed to the pathogenesis of pouchitis. METHODS: Patients were recruited and prospectively followed at a comprehensive pouch clinic. Pouch behaviour was clinically defined as a normal pouch [NP] or pouchitis. Patients completed Food Frequency Questionnaires [FFQs]. Faecal samples were analysed for microbial composition [16S rRNA gene pyrosequencing]. RESULTS: Nutritional evaluation was performed in 172 patients [59% females], and of these, faecal microbial analysis was performed in 75 patients (microbiota cohort: NP [n = 22], pouchitis [n = 53]). Of the entire cohort, a subgroup of 39 [22.6%] patients had NP at recruitment [NP cohort]. Of these, 5 [12.8%] developed pouchitis within a year. Patients at the lowest tertile of fruit consumption [<1.45 servings/day] had higher rates of pouchitis compared with those with higher consumption [30.8% vs 3.8%, log rank, p = 0.03]. Fruit consumption was correlated with microbial diversity [r = 0.35, p = 0.002] and with the abundance of several microbial genera, including Faecalibacterium [r = 0.29, p = 0.01], Lachnospira [r = 0.38, p = 0.001], and a previously uncharacterized genus from the Ruminococcaceae family [r = 0.25, p = 0.05]. Reduction in fruit consumption over time was associated with disease recurrence and with reduced microbial diversity [Δ = -0.8 ± 0.3, p = 0.008]. CONCLUSIONS: Fruit consumption is associated with modification of microbial composition, and lower consumption was correlated with the development of pouchitis. Thus, fruit consumption may protect against intestinal inflammation via alteration of microbial composition.

The outcome of ulcerative colitis patients undergoing pouch surgery is determined by pre-surgical factors.

BACKGROUND: Pouch surgery, a common intervention for ulcerative colitis (UC) complications, is often associated with the development of pouchitis. AIM: To identify predictors of pouch outcome in a cohort of patients with UC. METHODS: We conducted a retrospective unmatched case-cohort study in a tertiary IBD referral centre. Adult patients with UC were classified into the worst phenotype throughout follow-up: normal pouch, a form of chronic pouchitis (either chronic pouchitis or Crohn's like disease of pouch [CLDP]), or episodic recurrent acute pouchitis (RAP). Risk factors for pouchitis (chronic forms) were detected using statistical models. RESULTS: Two hundred and fifty-three pouch patients were followed up for 13.1±7.3 years. Only 71 patients (28.1%) maintained a favourable outcome of a sustained normal pouch. These patients were older at UC diagnosis (27.8±12.5 vs 23.0±11.4 years), had longer UC duration until surgery (13.4±9.5 vs 8.2±7.9 years), and had higher rates of referral to surgery due to nonrefractory (dysplasia/neoplasia) complications (42.3% vs 16.2%) compared with pouchitis patients. Median survival for sustained normal pouch was 10.8 years (95% CI 8.9-12.7 years), and it was longer in the nonrefractory group (20.3 vs 9.4 years for the refractory group, HR=2.37, 95% CI 1.25-3.52, P=.004). CONCLUSIONS: Most patients with UC undergoing pouch surgery will develop pouchitis. Patients operated for nonrefractory indications have a more favourable outcome. These results may contribute to pre- and post-surgical decision-making. The findings imply that the processes determining UC severity may be similar to that causing pouchitis.