In this study, we describe the changes associated with three months of intermittent fasting and probiotic yogurt consumption in a 72-year-old marathon runner with chronic lymphocytic leukemia for a number of years. Serum alpha-N-acetylgalactosaminidase (nagalase), a marker of inflammation and cancer cell proliferation, was significantly decreased at the end of a three-month observation. These results are consistent with immune modulating properties of certain probiotics based on the fermentation of milk and colostrum. Urinary excretion of non-metal toxicants that accumulate in adipose tissue such as Perchlorate, N-acetyl(2-hydroxypropyl)cysteine (NAHP), 2,4-Dichlorophenoxyacetic acid, 3-Phenoxybenzoic acid (3PBA), N-acetyl phenyl cysteine (NAP), Phenylglycoxylic acid (PGO), Monoethylphthalate (MEP) and 2-Hydroxyisobutyric Acid (2HIB) was significantly increased. These results are consistent with the weight loss (5 Kg) associated with intermittent fasting and with the known features of probiotics as detoxification tools. Consistent with certain toxicants acting as endocrine disruptors, we observed an increased elimination of toxicants and a 33% decrease of serum Thyroid Stimulating Hormone (TSH), suggesting a trend toward normalization of thyroid function. These results support the hypothesis that a combination of intermittent fasting with the consumption of specific probiotic yogurts may lead to immune modulation, detoxification and other improvements.Abbreviations(NAHP)N-acetyl(2-hydroxypropyl)cysteine(3PBA)3-Phenoxybenzoic acid(NAP)Nacetyl phenyl cysteine(PGO)Phenylglycoxylic acid(MEP)Monoethylphthalate(2HIB)2-Hydroxyisobutyric Acid(TSH)Thyroid Stimulating Hormone(Dr. JB)Dr. Jerry Blythe(CLL)chronic lymphocytic leukemia(IRB)Institutional Review Board(GcMAF)Gc protein-derived Macrophage Activating Factor