It was demonstrated that effervescent glutamine supplementation in HIV+ individuals treated with antiretroviral therapy (ART) increased CD4+ T lymphocytes, decreased inflammation biomarkers, and brought health benefits. This pilot study aimed to explore serum metabolite variations in the HIV+ group under ART after 30 days of supplementation with glutamine, and in comparison to the matched HIV- group. The group of HIV+ showed lower levels of choline, creatine, pyruvate, glutamate, lysine, and tyrosine when compared to the HIV- group. Glucose, lipids, lactate, glutamine, phenylalanine, threonine, and phenylalanine/tyrosine were higher in HIV+ patients under long ART. Serum metabolome variations were shown to be consistent with the health improvements observed in the HIV+ group after effervescent glutamine supplementation, which might aid in ART in HIV+ individuals.