A139 A LOW FODMAP DIET REDUCES SYMPTOMS IN INDIVIDUAL IBS PATIENTS BUT NOT MUCOSAL IMMUNE ACTIVATION OF NOCICEPTORS
Bibliographic record
Abstract
Lowering dietary FODMAPs in IBS patients reduces symptom severity in many cases yet the mechanism is poorly understood. It has been proposed that FODMAPs may activate mast cells in some patients. Mast cell mediators in turn could sensitize nociceptors innervating the gut, leading to exaggerated pain signalling. To determine if altering FODMAP intake modulates the excitability of nociceptors. Three IBS patients (Rome IV; 12 wk longitudinal crossover study) followed a low- and high-FODMAP diet. Mucosal sigmoid biopsies were collected during sigmoidoscopy and symptoms recorded using the IBS symptom severity score (IBS-SSS) at four 3 week intervals: 1) baseline, 2) after a run-in period and 3, 4) after each dietary intervention period; patients reporting score reductions of ≥50 after intervention were defined as responders. Mouse nociceptive dorsal root ganglia (DRG) neurons were cultured overnight with biopsy supernatants. Excitability of the neurons was assessed using perforated patch-clamp techniques and a decrease in rheobase was equated with increased excitability. Patients 1 and 2 (high FODMAP diet 1st) responded only to the low FODMAP diet compared to run-in (Table 1). Patient 3 (low FODMAP diet 1st) responded to both diets. Rheobases at the different time points did not differ in any patient (Table 1). The baseline rheobase of the IBS patients did not differ from control supernatants, in contrast to that seen previously with many patients. Low FODMAP dietary intervention reduced symptoms in this patient subset yet colonic biopsy supernatants had no effect on DRG neuron excitability. Thus, this pilot study suggests sigmoid mucosal immune activation may not underlie increased nociceptive signalling in this small subset of IBS patients. Further studies of other IBS patients is needed where baseline immune activation is present as well as studies of other sources of active metabolites e.g. the microbiota. Table 1: IBS symptom score and Rheobase measurementsTable 1: IBS symptom score and Rheobase measurements 1) Baseline, 2) Run-in, 3) Low FODMAP, 4) High FODMAP pA = Picoamps *Mean and Standard Deviation CIHR
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".