Therapeutic use of extracts containing proanthocyanidin including treating disorders, e.g., inflammatory disorders, e.g., inflammatory bowel disease, Crohn's disease, ulcerative colitis, indeterminate colitis, microscopic colitis, collagenous colitis, and irritable bowel syndrome. Mmethods of increasing a subject's immunological resistance to an infection and/or treating the infection. The infection can be, e.g., a bacterial, viral, or fungal infection. The methods can include, e.g., selecting a subject that has, or is at risk of developing, an infection, e.g., a bacterial, viral, or fungal infection, or a combination thereof; providing a composition comprising at least about 10% proanthocyanidin by weight; and administering to the subj ect an amount of the composition to the subject, to thereby increase a subject's immunological resistance to an infection and/or to treat the infection.