Psyllium (Plantago ovata, ispaghula husk)

Psyllium is the first-line soluble fibre in chronic functional constipation per ACG 2014 monograph and NICE recommendations. AEMPS registered Plantaben and Cenat with the indication of functional constipation and maintenance of normal defecation. Christodoulides 2016 meta-analysis (7 RCTs, 405 patients) showed increased stool frequency and improved consistency on psyllium 10-20 g/day × 4 weeks. EFSA 2013 approved a health claim for psyllium on increased stool bulk at minimum 7 g/day. ACG 2014 in chronic constipation lists first-line: soluble psyllium fibre 7-10 g/day with ample water, osmotic laxatives (PEG/macrogol) if insufficient, stimulant laxatives (bisacodyl, sennosides) for persistent constipation, novel drugs (linaclotide, prucalopride, lubiprostone) for refractory constipation. Dose: start at 3.5 g 1-2 times daily, gradually increase to 7-10 g/day with minimum 250 mL of water per dose.

Psyllium is one of the few soluble fibres with evidence in irritable bowel syndrome, especially IBS-C. Moayyedi 2014 meta-analysis (14 RCTs, 906 patients) showed moderate global IBS symptom improvement with soluble fibre (psyllium, ispaghula), but not insoluble (wheat bran). NICE NG61 IBS 2017 in IBS-C and mixed forms lists soluble psyllium fibre with gradual dose increase first-line. ACG 2021 IBS guideline gives a strong recommendation for soluble fibre use (psyllium, ispaghula). Evidence base is stronger than for probiotics. In IBS-D, psyllium may worsen bloating in some patients – individual dose titration required. Effect develops over 2-4 weeks of use.

Psyllium is one of the few dietary supplements with confirmed cardiometabolic benefit. EFSA 2010 approved the health claim: «psyllium husk contributes to maintenance of normal blood cholesterol» at minimum 7 g/day. Brown 1999 meta-analysis (8 RCTs) and updated Wei 2009 showed 5-10% LDL reduction on psyllium 7-10 g/day × 8 weeks. FDA in the US allowed a heart-health claim for psyllium from 1998. ACC/AHA in hypercholesterolaemia list statins (atorvastatin, rosuvastatin) first-line; statin intolerance or insufficient effect – ezetimibe, PCSK9 inhibitors (alirocumab, evolocumab), bempedoic acid. Psyllium may be used as adjunct to statin for additional 5-10% LDL reduction but does not replace statin in high cardiovascular risk patients. If psyllium was recommended as a statin substitute in coronary disease, prior myocardial infarction or stroke, consider seeking a second opinion from a cardiologist.