Clinical study

Epidemiology of gout and hyperuricemia: A long-term population study☆

In contrast to traditional agriculture, microbial protein (MP) production is highly efficient in nitrogen (N) usage and can be employed to valorize a variety of recovered resources, thereby increasing the overall sustainability of food production. The present study aimed to establish the potential of seven recovered N sources originating from different waste streams for MP production using ethanol and acetate as growth substrates. The evaluation was based on specific growth rate, biomass yield, nutritional quality (i.e. macromolecular composition, amino acid (AA) and lipid profile) and food safety (i.e. concentration of heavy metals, polyaromatic hydrocarbons (PAH), pesticides and antibiotics) of the MP. The majority of the recovered N sources did not affect the kinetics and had a minor impact on the biomass yield, compared to their commercial equivalents. The nutritional content of the biomass was similar to soy flour and did not show major variations in AA and lipid profile for the different recovered N sources. Considering the heavy metal content, an average-weighing adult should not consume >53–213 g of the microbial biomass produced on recovered N per day due to its high copper content. A substantial amount of PAH were also found in the biomass. A daily consumption of 20 g/person/day would impose 2.0–2.8 times higher dietary exposure than the mean PAH exposure through nutrition in the EU, indicating a potential concern for human health. On the other hand, the biomass was free of antibiotics, and the traces of pesticides found did not raise any major concern for food applications. Based on the results of this work, no evidence was found to restrict the application of microbial biomass produced on recovered nitrogen as food.

Short-term randomized trials suggest that a 500 mg/d vitamin C supplement reduces serum urate, whereas observational studies show vitamin E is inversely associated with gout risk.

We evaluated the effect of supplemental vitamin C (prespecified primary exposure) and vitamin E (prespecified secondary exposure) on new diagnoses of gout.

We performed a post hoc analysis of data from the Physicians’ Health Study II, a randomized, double-blind, placebo-controlled factorial trial of randomized vitamin C (500 mg/d) and vitamin E (400 IU every other day). The primary outcome was new gout diagnoses, self-reported at baseline and throughout the follow-up period of ≤10 y.

Of 14,641 randomly assigned male physicians in our analysis, the mean age was 64 ± 9 y; 1% were Black, and 6.5% had gout prior to randomization. The incidence rate of new gout diagnoses during follow-up was 8.0 per 1000 person-years among those assigned vitamin C compared with 9.1 per 1000 person-years among those assigned placebo. The vitamin C assignment reduced new gout diagnoses by 12% (HR: 0.88; 95% CI: 0.77, 0.99; P = 0.04). These effects were greatest among those with a BMI <25 kg/m ² (P-interaction = 0.01). Vitamin E was not associated with new gout diagnoses (HR: 1.05; 95% CI: 0.92, 1.19; P = 0.48).

Vitamin C modestly reduced the risk of new gout diagnoses in middle-aged male physicians. Additional research is needed to determine the effects of higher doses of vitamin C supplementation on serum urate and gout flares in adults with established gout. The Physicians’ Health Study II is registered at clinicaltrials.gov (identifier: NCT00270647).

Microbial protein (MP) is back on the table after decades of slumbering interest. One-carbon (C1) substrates are attractive for MP production due to their efficient production from CO₂ and renewable electricity, linking carbon capture to food while circumventing agriculture. Here we compared all reported combinations of C1 (formate/methanol/methane) and microorganisms (bacteria/yeasts) in terms of engineering and biomass quality parameters, focusing on the amino acid match with human requirements. This meta-analysis based on >100 studies suggests that methanol is the most promising C1, and methanol-grown microorganisms seem most nutritional with bacteria and yeasts having different merits. More sustainable MP could be produced if metabolic engineering tools yielding microorganisms with more efficient C1 assimilation pathways and steered amino acid profiles are deployed.

Alternative protein sources such as microbial protein (MP) are currently considered to alleviate the burden that food production exerts on the environment. Even though MP production is highly efficient in land and nutrient utilization, their carbon footprint should be improved. Here we propose the use of CCU as a driver for heterotrophic MP production. By comparing different MP production routes starting from liquid substrates derived from CO₂ (i.e., formate, acetate, methanol, and ethanol) and their respective metabolic pathways, the potential of this concept as a carbon–neutral food or feed production process was estimated. Acetate and ethanol appear to be the most beneficial substrates for the integrated CCU-to-MP process in terms of electricity demand (acetate: 25 – 54 kWh/kg_product, ethanol: 28 – 56 kWh/kg_product). Moreover, recycling CO₂ enables a carbon-negative protein production process by 2030 (considering the projected CO₂ emissions from electricity in the EU: 0.096 kg_CO2-eq/kWh) for formate, acetate, and ethanol (-1.1 up to 13 kg_CO2-eq/kg_product).

Hyperuricemia is a common condition in patients with chronic kidney disease and end-stage kidney disease. It occurs even after kidney transplant because of the use of calcineurin inhibitors and transplanted kidney failure. We describe the case of a patient with end-stage kidney disease who had multiple gouty arthritis with tophi formation despite receiving appropriate treatment but was successfully cured after kidney transplant.

A 36-year-old male patient undergoing hemodialysis treatment was treated with febuxostat for multiple gouty arthritis and underwent tophi removal twice. He received a deceased donor kidney transplant 10 years after dialysis treatment. He received immunosuppressants (basiliximab, tacrolimus, mycophenolate mofetil) and steroids. Results of renal biopsy performed on days 7 and 21 postoperation showed no specific findings and normal renal function. The uric acid level before transplant was 3.1 mg/dL, and when renal function was normal, it reached 6-7 mg/dL and remained stable. Although hyperuricemia was still present, the tophi disappeared 3 months after transplant. It is presumed that the high-dose steroids interfered with the activation of inflammatory responses during tophi formation, which may have caused the tophi to disappear. It is also presumed that the patient adhered to the diet well after transplant, which suppressed tophi formation.

Our findings suggest that disappearance of multiple tophi and arthritis in patients undergoing hemodialysis can be achieved with kidney transplant, especially when uric acid–lowering drugs are not effective.

Meat alternatives are predominantly plant centered food products designed to mimic the taste, texture, look, and functionality of meat products. It is also called meat analog, meat substitute, and imitation meat. Plant-based meat aims to offer consumers familiar meals with diversified and a lighter impact on the earth and human health. The use of plant proteins is more economical and sustainable, while the conversion of feed into animal protein requires a large amount of arable land, water, and energy, leading to deforestation, land degradation, and biodiversity loss. Plant-rich proteins are the nutritious proteins and future-proof protein supply that guarantee future food security. Besides, plant-based, fungal protein and insect-based products also other potential meat alternatives prospects. They can be expanded directly as meat alternatives with an identic sensory quality, better physicochemical properties, and offer healthy images. These alternative protein sources are not only healthy but also fast, convenient, and non-perishable, which means require little attention than animal proteins.