Psyllium, a soluble fiber derived from the husks of Plantago ovata seeds, has scientific backing for its use in supporting some forms of colitis, particularly ulcerative colitis (UC). Several randomized controlled trials and meta-analyses have demonstrated that psyllium supplementation can be beneficial in maintaining remission in UC patients. For example, a landmark study published in the British Medical Journal in 1998 compared psyllium with mesalazine and found that both agents were similarly effective in maintaining remission over a 12-month period. The proposed mechanism involves psyllium’s ability to ferment in the colon, producing short-chain fatty acids such as butyrate, which serve as an energy source for colonocytes and may have anti-inflammatory effects.

However, the evidence base is not as robust as for standard pharmaceutical therapies, and psyllium is generally considered as adjunctive rather than primary therapy. There is less evidence for its use in Crohn’s disease or in acute flares of colitis, and fiber supplements like psyllium may be contraindicated in patients with strictures or severe disease due to risk of obstruction. Nonetheless, psyllium is widely recognized in clinical guidelines as an option for patients with mild-to-moderate UC in remission who can tolerate increased fiber intake. The use of psyllium in colitis is thus supported by scientific studies, but the strength of evidence is moderate, not high.