A cellular constituent is lysed from, produced by and/or isolated from one or more bacteria from the genus Bacteroides, and the cellular constituent, a derivative thereof, and/or one or more bacteria from the genus Bacteroides, or a modified form thereof, is employed in compositions and methods for modulating an inflammatory response. Such methods include methods of treating, delaying the onset of or reducing the symptoms of one or more inflammatory conditions/diseases, including corporal or gastrointestinal inflammation, for example, Irritable Bowel Syndrome, Crohn's Disease, or colitis, and/or associated diseases such diabetes, asthma, multiple sclerosis, cancer, rheumatoid arthritis, gingivitis, atopic diseases, for example, hay fever, food allergies, eczema, rhinitis, dermatitis, conjunctivitis, atopic syndrome and keratosis pelaris, ocular inflammatory disease, strokes, cardiovascular disease, depression, atherosclerosis and hypertension, and comprise administering a composition comprising one or more natural and/or modified bacteria of the genus Bacteroides, and/or a cellular constituent lysed from, produced by, or isolated from one or more natural and/or modified bacteria from the genus Bacteroides, or a derivative thereof.
