Claudia Herrera-deGuise, MD

Credit: Linkedin

New evidence shows patients with ulcerative colitis who are in remission have their disrupted gut microbiota restored in a way that is comparable to healthy individuals without inflammatory bowel disease (IBD).¹

A team, led by Claudia Herrera-deGuise, MD, Unitat Atenció Crohn-Colitis, Digestive System Department, Hospital Universitari Vall d’Hebron, explored whether patients with ulcerative colitis who reach long-term clinical, endoscopic, and histological remission show a gut microbial ecosystem that is similar to a healthy control group.

Gut Microbiota

In microbiome studies, investigators have frequently reported that low gut microbial richness and diversity is present in patients with ulcerative colitis.

In the study, the investigators collected 184 stool samples from 111 participants, including patients with ulcerative colitis in long remission, short remission, and flare, as well as healthy control subjects. They also analyzed microbiota by amplicon sequencing (16S ribosomal RNA) and quantitative polymerase chain reaction for specific taxa.

Every participant with ulcerative colitis in remission was followed up with for up to 2 years.

Diversity

The results show a decrease in species diversity and richness, as well as an underrepresentation of butyrate producers and a gain in potentially harmful bacteria in samples from patients in the disease-flare and short-remission groups.

On the other hand, Chao1 and Shannon indexes of diversity did not differ among patients in long remission and the healthy control group.

In addition, the patients in long-remission also presented with fecal bacterial composition that was similar to what was found in the healthy control group and there was a positive correlation between Akkermansia muciniphila abundance and time in remission (r_s = 0.53, P <.001).

After conducting a logistic regression analysis, the investigators found a high Shannon index (odds ratio [OR], 4.83; 95% confidence interval [CI], 1.5-20.6) or the presence of A. muciniphila (OR, 4.9; 95% CI, 1.12-29.08) in fecal samples at entry was independently associated with clinical remission over a follow-up period of 24 months.

“UC patients who achieve long-term remission show evidence of substantial recovery of the gut microbial ecosystem in terms of diversity and composition. Recovery may just reflect adequate control of inflammatory activity, but higher bacterial diversity or the presence of A. muciniphila in fecal samples predicts flare-free outcomes,” the authors wrote.

Gut Microbiota and the COVID-19 Vaccine

Earlier this year, investigators found Patients with IBD who are treated with anti-tumor necrosis factor (anti-TNF) medications are at a risk of a lower serological response from COVID-19 vaccinations, largely because of a lack of diversity in the gut microbiota.²

A team, led by James L. Alexander, Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, examined whether the gut microbiota and metabolome might explain variation in anti-SARS-CoV-2 vaccination responses in immunosuppressed patients with IBD.

The results show 39.5% (n = 17) of patients had a serological response below the geometric mean, while gut microbiota diversity was lower in below average responders (P = 0.037). The results also show Bilophila abundance was linked to better serological responses, while Streptococcus was associated with a poorer response.

The investigators also found distinct differences in the fecal metabolome between above and below average responders (OPLS-DA R_2X 0.25; R_2Y 0.26; Q₂ 0.15; CV-ANOVA P = 0.038).

Better responders also had higher levels of trimethylamine, isobutyrate, and omega-muricholic acid, while poorer response was linked to succinate, phenylalanine, taurolithocholate, and taurodeoxycholate.

References:

1. Claudia Herrera-deGuise, MD, Encarna Varela, MD, Guillaume Sarrabayrouse, PhD, Marta Pozuelo del Río, PhD, Virginia Robles Alonso, MD, Natalia Borruel Sainz, MD, Francesc Casellas, MD, Luis Fernando Mayorga, MD, Chaysavanh Manichanh, PhD, Fernando Azpiroz Vidaur, MD, Francisco Guarner, MD, Gut Microbiota Composition in Long-Remission Ulcerative Colitis is Close to a Healthy Gut Microbiota, Inflammatory Bowel Diseases, 2023;, izad058, https://doi.org/10.1093/ibd/izad058

2. Walter, K. (2023, January 12). Gut microbiota forecasts serological response for COVID-19 vaccines in IBD patients. HCP Live. Retrieved April 22, 2023, from https://www.hcplive.com/view/gut-microbiota-forecasts-serological-response-covid-19-vaccines-ibd-patients