A novel Monash Pouch diet in patients with an ileoanal pouch is tolerable and has favorable metabolic luminal effects

Abstract

Aims: To evaluate a whole-food diet strategy (the Monash Pouch diet [MPD]) designed based on the interacting roles dietary factors play with pouch health. Specifically, its tolerability and acceptability, whether it achieved its dietary and metabolic goals, and the effects on symptoms and inflammation were examined.

Methods: In a 6-week open-label trial, patients with ileoanal pouches educated on the MPD were assessed regarding diet tolerability and acceptance, food intake (7-day food diaries), pouch-related symptoms (clinical pouchitis disease activity index), and, in 24-h fecal samples, calprotectin, fermentative biomarkers, and volatile organic compounds (VOC).

Results: Of 12 patients, 6 male, mean (SD) age 55 (5) and pouch age 13 (2) years, one withdrew with partial small bowel obstruction. Tolerability was excellent in 9 (75%) and acceptance was high (81%). Targeted changes in dietary intake were achieved. Fecal branched- to short-chain fatty acid ratio increased by median 60 [IQR: 11-80]% (P = 0.02). Fecal VOCs for 3 compounds were also increased, 2-methyl-5-propan-2-ylcyclohexa-1,3-diene (Fold-change [FC] 2.08), 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane (FC 3.86), propan-2-ol (FC 2.10). All six symptomatic patients achieved symptomatic remission (P = 0.03). Fecal calprotectin at baseline was 292 [176-527] μg/g and at week 5 was 205 [148-310] μg/g (P = 0.72).

Conclusion: Well tolerated and accepted, the MPD achieved targeted changes in intakes and fermentation of carbohydrates relative to that of protein. There were signals of improvement in symptoms. These results indicate the need for a randomized-controlled trial. (Trial registration: ACTRN12621000374864; https://www.anzctr.org.au/ACTRN12621000374864.aspx).

Keywords: diet; fermentable oligo‐, di‐ and monosaccharides and polyols; pouch; pouchitis; protein fermentation; ulcerative colitis.

Figure 1

Diet tolerability over the duration of the study in based on (a) pouch symptoms and (b) pouchitis status at entry. (a) , Symptomatic; , Asymptomatic; , Median tolerability. (b) , Pouchitis; , No pouchitis; , Median tolerability.

Figure 2

Fecal metabolite concentrations during the baseline period and after 5 weeks of the Monash Pouch diet. , Pouchitis; , No pouchitis.

Figure 3

Principal components analysis plot of VOC patterns between (a) baseline and following 5 weeks of the Monash Pouch diet as well as (b) between patients with pouchitis and without pouchitis at baseline and post‐dietary intervention. The explained variance are in brackets. (c) Heatmaps showing differences in VOC patterns between patients with and without pouchitis at baseline and following dietary intervention. (d) Graph showing fold changes of key volatile organic compounds identified to be altered from pre‐ to post‐dietary intervention. Each dot represents an individual patient. BL = Baseline; FU = week 5 of dietary intervention. (a) , Baseline; , Week 5 diet intervention; (b) , BL no pouchitis; , BL pouchitis; , FU no pouchitis; , FU pouchitis; (c) Class—, BL no pouchitis; , BL pouchitis; Class—, FU no pouchitis; , FU pouchitis.

Figure 4

Clinical and fecal indices during the baseline period and after 5 weeks of the Monash Pouch diet. PDAI, pouch disease activity index; ODS, obstructive defecatory symptom; FC, fecal calprotectin.