IBS is thought to affect up to 15% of the population and is characterized by abdominal pain, bloating, gas, and alternating bowel habits. The low FODMAP (fermentable, oligo-, di-, mono-saccharides, and polyols) diet is commonly used as a first-line therapy and restricts dietary intake of fermentable short-chain carbohydrates including the oligosaccharides, fructans, and galacto-oligosaccharides (GOS). FODMAPs are foods (ex. cow milk, wheat) that cause symptoms due to poor absorption in the small intestine, resulting in an osmotic effect increasing water delivery into the gut, and rapid fermentation by the colonic microbiota leading to A LOT OF GAS. This extra water and gas production distends the bowel, worsening the symptoms of IBS. FODMAPs also have effects on gut microbiota, immune function, and mucosal permeability that could also affect IBS symptoms. Reducing dietary intake of FODMAPs provides an improvement of IBS symptoms in the majority of patients. In fact, up to 50% of patients with IBS-D had adequate symptom relief of their pain and bloating.
One issue with the low FODMAP diet is that it is ‘anti-prebiotic’ in the effect it has on raising stool pH and reducing stool Bifidobacteria in the microbiome as well as short-chain fatty acids like butyrate which are important to colonic epithelium and barrier function. Low concentrations of bifidobacteria have been associated with higher pain levels in IBS. What can you do about this? Take a prebiotic & probiotic while you’re on low FODMAP!
1. Probiotic: Studies have shown that co-administration of the probiotic VSL#3 increased numbers of Bifidobacterium species in the microbiome, compared with placebo, and may be given to restore these bacteria to patients on a low FODMAP diet. In addition, Align contains Bidifobacterium and could be considered if VSL#3 is too pricey.
2. Prebiotic: Studies showed the prebiotic B-galacto-oligosaccharide resulted in significantly greater symptom improvement between controls (30.4%), those on the low FODMAP diet alone (50%) and those on the low FODMAP diet + prebiotic (66.7%). Other prebiotics to consider are prebiotin and benefiber.
So if you suffer from IBS and are on a low FODMAP diet, make sure you're protecting your micro biome's diversity with a pre & probiotic!