Beet fiber, like other dietary fibers, is sometimes recommended for diverticulitis, particularly in the management and prevention of diverticulosis (the presence of diverticula in the colon) and to help prevent flare-ups of diverticulitis rather than treating acute inflammation. The recommendation for increased fiber intake in diverticular disease has a scientific basis, primarily derived from observational studies indicating that populations with higher fiber intakes have lower prevalence of diverticular disease. Soluble and insoluble fibers help promote regular bowel movements and may decrease intracolonic pressure, theoretically reducing the risk of diverticula formation and inflammation.

However, the direct evidence for beet fiber specifically (as opposed to generic dietary fiber) is limited. Most clinical research and guidelines refer to dietary fiber from a variety of sources, and do not single out beet fiber as uniquely beneficial. The supporting evidence for fiber in general is moderate, with some randomized controlled trials suggesting a benefit for symptom management in diverticular disease, but less clear benefit for preventing acute diverticulitis episodes. There is a lack of robust, high-quality clinical trials directly evaluating beet fiber for this condition.

In summary, while there is scientific validation for the use of dietary fiber in diverticular disease, the evidence for beet fiber specifically is limited and largely extrapolated from broader research on fiber. Therefore, the evidence level is rated at 2 out of 5.