Most healthy adults can increase fibre through food safely, but some people should be careful with fibre supplements.
Be cautious if you have difficulty swallowing, a history of bowel narrowing, severe constipation, unexplained stomach pain, vomiting, bleeding, recent gut surgery or ongoing digestive disease. Psyllium husk and other bulking fibres may not be suitable without medical guidance in such cases.
Medicine users should also be careful. Fibre can affect absorption or timing of some medicines. Thyroid tablets, diabetes medicines, cholesterol medicines, iron, calcium and long-term prescriptions should be discussed with a doctor or pharmacist before adding a daily fibre supplement.
Allergies matter too. Some people may react to specific fibre sources. Others may be sensitive to sweeteners, flavours or additives in the product.
Start low even if you are healthy. Drink enough water. Do not mix multiple new gut products together. Stop and seek advice if symptoms become unusual or severe.
Food fibre from dal, vegetables, fruit and whole grains is a good base for most people, but supplement use needs more care.
The safest fibre routine is not the strongest one. It is the one that fits your body, medicines and health status.
Being cautious here is not overreacting. A five minute conversation with a doctor is cheaper than a bad reaction discovered the hard way.