On further history, it was discovered that the family had been using alkaline water as an alternate source of oral fluids given its reported health benefits. Alkaline water is advertised as negatively charged water with a pH of 8–10. These properties are marketed to provide significant health benefits including increased energy levels, reduced effects of ageing and stress and reduced incidence of illness and disease. Alkaline water contains calcium and magnesium carbonate, both exogenous sources of absorbable alkaline. The consumption of alkaline water in this case resulted in a milk-alkali syndrome with hypercalcaemia, metabolic alkalosis and an acute on chronic kidney injury. It was not detected for several months, and as a result, had a significant negative impact on this patient and his family. He required frequent venepuncture, increased clinical reviews (further complicated by the current COVID-19 pandemic) and regular titration of medications. Fortunately, on cessation of the alkaline water, his creatinine returned to baseline and calcium and acid–base normalised.

<b>Background/Objectives</b>: Hyperuricemia (HUA) is the second most common metabolic disease in China (24.5% in males, 3.6% in females), which can induce multiple complications such as gout and diabetes. Existing urate-lowering drugs have significant hepatorenal toxicity, necessitating safe lifestyle interventions. Electrolyzed alkaline water (EAW) as daily drinking water has shown preliminary effectiveness, but it lacks randomized controlled evidence and mechanistic studies at the microbiome-metabolome interface. <b>Methods</b>: We conducted a 12-week randomized controlled trial in 40 adults aged 18-65 years with elevated serum uric acid (SUA). Participants consumed either 1.5 L/day of EAW (pH 8.5-9.5) or purified water (pH 7.0). Clinical indicators, quality of life (SF-36), gut microbiota, and gut metabolomics were comprehensively assessed to evaluate intervention efficacy and explore potential mechanisms. <b>Results</b>: After 12 weeks, the EAW group exhibited a larger reduction in serum uric acid than the control group, along with improvements in selected physical health-related quality-of-life measures. Modest differences in gut microbial composition were observed between groups. Metabolomic analyses identified group-level differences in metabolites enriched in pathways related to purine metabolism and other urate-associated metabolic processes. <b>Conclusions</b>: This pilot randomized controlled trial suggests that consumption of EAW is associated with a modest reduction in serum uric acid. Exploratory multi-omics analyses indicate concurrent changes in gut microbiota and metabolic profiles. These findings support further investigation of electrolyzed alkaline water as a potential adjunctive, non-pharmacological option for hyperuricemia in larger and longer-term studies. <b>Ethics:</b> This trial was registered with the Chinese Clinical Trial Registry under the identifier ChiCTR2500100190. Ethical approval for the present study was granted by the Nankai Univ Hydration is a fundamental determinant of metabolic health, yet the specific impact of water quality on uric acid regulation remains under-explored. Electrolyzed alkaline water (EAW)—produced via electrolysis to possess an alkaline pH and a negative oxidation-reduction potential (ORP)—has been proposed as a functional beverage. While some preliminary studies suggest that EAW may modulate metabolic parameters and antioxidant status [ 14 , 15 , 16 , 17 ], evidence for urate-lowering effects is largely derived from animal studies, and corresponding data from well-controlled human studies are currently lacking [ 18 ]. Therefore, we conducted a 12-week randomized controlled trial comparing electrolyzed alkaline water (pH 8.5–9.5) with purified neutral water (pH 7.0) No clinically relevant adverse events were observed in either group, indicating good metabolic and hepatic–renal safety of the intervention. 3.3. Changes in Health-Related Quality of Life (SF-36) Scores of the Short-Form 36 Health Survey (SF-36) were used to evaluate changes in physical and mental health domains during the 12-week intervention. Overall, participants consuming alkaline water showed modest improvements in several physical domains compared with controls, whereas psychological dimensions remained essentially unchanged. Specifically, Role-Physical (RP) and Bodily Pain (BP) scores increased slightly in the alkaline water group. Other subscales—including Physical Functioning (PF), General Health (GH), Vitality (VT), Social Functioning (SF), Role-Emotional (RE), and Mental Health (MH)—showed no significant group-by-time interactions ( p > 0.05), suggesting that the intervention did not markedly alter mental or social well-being within the 12 weeks. The Mental Component Summary (MCS) also remained stable across groups ( p > 0.05). Together, these results suggest that 12 weeks of daily intake of alkaline water significantly improved physical-related quality-of-life dimensions (RP, BP, and PCS), while maintaining mental health stability without adverse psychological effects. 3.4. Additionally, EAW may influence the expression of urate transporters URAT1 and GLUT9 via its antioxidant and anti-inflammatory properties, which have been shown to improve renal function in murine models [ 18 ]. Collectively, these findings provide indirect support for a potential role of EAW in urate homeostasis. In addition, this study found that after 12 weeks of intervention, serum albumin levels increased slightly in the alkaline water group but decreased in the control group. These findings indicate that alkaline water intake had a significantly greater effect on maintaining or improving serum albumin levels than the control. The present study possesses several notable strengths. First, it is a randomized, double-blind, controlled human trial that systematically evaluated the urate-lowering efficacy of electrolysed alkaline water (EAW) in adults with hyperuricemia. Second, by integrating gut microbiota profiling with untargeted gut metabolomics, this study provides a comprehensive view of the gut ecological and metabolic responses to EAW intervention. The combined use of multi-omics analysis enables the identification of microbe–metabolite networks and metabolic pathways potentially involved in urate homeostasis. Future animal and mechanistic studies are warranted to determine whether the observed intestinal microbial shifts directly mediate urate metabolism and to further delineate the underlying biological mechanisms. 5. Conclusions In summary, this 12-week pilot randomized controlled trial provides preliminary evidence that consumption of electrolyzed alkaline water was associated with modest reductions in serum uric acid and concurrent changes in gut microbial composition and metabolic profiles in adults with hyperuricemia. These multi-omics observations suggest that EAW may influence uric acid homeostasis through gut microbiota and its associated metabolic processes.