Paper Authors and Title

Chiara Del Greco (Atlantic Technological University), Paul Hartel, “Colonic Lymphoid Aggregate Histology is Associated with Gut Microbial Flora Content in Symptomatic Patients with Normal Colonoscopy”


Lymphoid aggregates are an accumulation of lymphoid cells found in many areas including the gastrointestinal tract.  These lymphoid aggregates are often regarded as benign and are not consistently reported by pathologists. However, colonic lymphoid aggregates have been associated with persistent diarrhoea in a subset of patients without colonic pathology and with normal colonoscopy findings.

In this study, lymphoid aggregates were evaluated in 40 symptomatic patients from otherwise normal colonic biopsies with normal colonoscopy findings to determine the relationship between clinical and pathologic parameters. The aggregates were evaluated by recording size, morphology, and frequency per sample. It was hypothesised that abnormal microbial content may be linked with elevated numbers of lymphoid aggregates found in the colon. Gram stains were carried out to characterise the bacteria present in the samples.

It was found that the presence of Gram-negative cocci, short bacilli and long bacilli were associated with larger more well-circumscribed lymphoid aggregates. For some patients, specific colonic microbial content may be associated with lymphoid response and symptoms. Further characterisation of the microbiota present in the samples is recommended.