Abstract: The present invention provides methods for determining if a patient is likely to benefit from a cancer treatment, by determining if said patient has a gut dysbiosis with an over representation of certain bacterial species. The present invention also provides probiotic strains to improve the efficacy of a cancer treatment, especially chemotherapy, in patients in need thereof.

Abstract: A process of obtaining an .alpha.-lactalbumin enriched product from whey of various origins is disclosed. A first ultrafiltration is carried out on unpasteurized raw whey with membranes having cut-off greater that 5,000 (e.g. 50,000) at a pH between 6:3 and 7 (e.g. 6.6) and a temperature between 30.degree. and 60.degree. C. thereby retaining whey proteins. The ultrafiltrate then undergoes a second ultrafiltration with a membrane capable of retaining .alpha.-lactalbumin (cut-off about 1,200 and 2,000) which is preferably diafiltration. Depending on whether starting whey is acid whey or sweet whey the resulting product may contain practically no CMP or some (e.g. 25%). The resulting product is useful as a mother's milk substitute, pharmaceutical, intensive care or therapeutic food, or tryptophan enriched nutrient.