Nitrogen is the principal component of intestinal gas. Nature is normally a good intestinal housekeeper. Both bile and hydrochloric acid have antiseptic effects. Digestive enzymes assist by keeping down the presence of undigested foods. Many foods have a beneficial effect in maintaining the intestinal environment.
Some foods are to be watched with a suspicious eye.
Recently, a number of articles have appeared in medical journals reporting on malabsorption syndrome caused by the eating of a common food. The offending factor discussed is gluten. Gluten is the substance in wallpaper paste which provides it with its adhesive quality. It is a protein. Ordinarily it is digested, but some may have difficulty with its digestion and it may coat the intestinal tract.