Smart proteins as a new paradigm for meeting dietary protein sufficiency of India: a critical review on the safety and sustainability of different protein sources

India, a global leader in agriculture, faces sustainability challenges in feeding its population. Although primarily a vegetarian population, the consumption of animal derived proteins has tremendously increased in recent years. Excessive dependency on animal proteins is not environmentally sustainable, necessitating the identification of alternative smart proteins. Smart proteins are environmentally benign and mimic the properties of animal proteins (dairy, egg and meat) and are derived from plant proteins, microbial fermentation, insects and cell culture meat (CCM) processes. This review critically evaluates the technological, safety, and sustainability challenges involved in production of smart proteins and their consumer acceptance from Indian context. Under current circumstances, plant-based proteins are most favorable; however, limited land availability and impending climate change makes them unsustainable in the long run. CCM is unaffordable with high input costs limiting its commercialization in near future. Microbial-derived proteins could be the most sustainable option for future owing to higher productivity and ability to grow on low-cost substrates. A circular economy approach integrating agri-horti waste valorization and C1 substrate synthesis with microbial biomass production offer economic viability. Considering the use of novel additives and processing techniques, evaluation of safety, allergenicity, and bioavailability of smart protein products is necessary before large-scale adoption.

Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota

Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.

The effects of spirulina supplementation on serum iron and ferritin, anemia parameters, and fecal occult blood in adults with ulcerative colitis: A randomized, double-blinded, placebo-controlled trial

BACKGROUND & AIMS

The present clinical trial aimed to evaluate the efficacy of spirulina administration on serum iron, ferritin, anemia parameters, and fecal occult blood test (FOBT) in adults with ulcerative colitis (UC).

METHODS

Eighty participants with UC were randomly assigned to take, either 1 g/day (two 500 mg capsules) spirulina (n = 40) or placebo (n = 40) in a double-blinded clinical trial for eight weeks. Dietary intake, physical activity status, serum iron and ferritin levels, anemia parameters, and FOBT were assessed in each participant at baseline and following the intervention. Seventy-three participants completed the trial.

RESULTS

Our results indicated significantly increased (p = 0.04) serum iron after eight weeks of spirulina supplementation compared to the placebo group. The spirulina group also demonstrated significantly increased mean corpuscular volume (p = 0.004) whereas red blood cell count (p = 0.01) and hematocrit (p = 0.03) were significantly lowered in the placebo group. No significant changes in FOBT outcomes were seen between groups at baseline (p = 0.12) and the end of the trial (p = 0.34). Eight weeks of 1 g/day spirulina supplementation improved anemia parameters in adults with UC compared to placebo.

CONCLUSIONS

These outcomes suggest that spirulina administration may be beneficial in the management of anemia in UC. Further clinical trials of longer duration are necessary to corroborate and expand our findings. Registered at: http://www.IRCT.ir (code: IRCT20170802035460N3).

Safety assessment of Synechococcus sp. PCC 7002 biomass: genotoxicity, acute and subchronic toxicity studies

Synechococcus sp. PCC 7002 has the potential to be used as a new resource of food owing to its nutritional and functional benefits. However, little information has been published regarding the safety of Synechococcus sp. PCC 7002 biomass (SynB). The present study assessed genotoxicity, acute and subchronic toxicity of SynB for the first time. SynB did not show any genotoxicity based on the Ames test, mammalian erythrocyte micronucleus test, and mouse primary spermatocyte chromosome aberration test. SynB administered by gavage in mice at a dose of 10 g per kg body weight did not induce death or toxicity based on the acute toxicity study, indicating the median lethal dose value of SynB was over 10 g per kg body weight. In the 90-day subchronic toxicity study, no treatment-related mortality or clinical sign was noted with SynB at doses of 5 and 10 g per kg body weight in mice, and there was no adverse effect of SynB on food consumption, organ coefficients, blood biochemistry, urinalysis and histopathology. The Non Observed Adverse Effect Level for SynB in female and male mice was not less than 10 g per kg body weight per day based on subchronic toxicity. These results support the safe use of SynB as a new food raw material.

Impact of Regular Intake of Microalgae on Nutrient Supply and Cardiovascular Risk Factors: Results from the NovAL Intervention Study

A 14-day randomized controlled study with a parallel design was conducted with 80 healthy participants. Intervention groups I (IG1) and II (IG2) received a defined background diet and consumed a smoothie enriched with either 15 g of Chlorella dry weight (d.w.) or 15 g of Microchloropsis d.w. daily. Control group II (CG2) received a defined background diet without the smoothie. Control group I (CG1) received neither. Blood samples and 24-h urine were collected at the beginning and the end of the study. Serum concentrations of 25-hydroxyvitamin D3, vitamin D3, selenium, iron, ferritin, transferrin saturation, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, non-HDL cholesterol and the LDL-cholesterol/HDL cholesterol ratio decreased in IG1 (p < 0.05), while 25-hydroxyvitamin D2 increased (p < 0.05). In IG2, vitamin D3, 25-hydroxyvitamins D2 and D3 decreased (p < 0.05), while concentrations of fatty acids C20:5n3 and C22:5n3 increased. Serum and urine uric acid increased in IG1 and IG2 (p < 0.05). Microchloropsis is a valuable source of n3 fatty acids, as is Chlorella of vitamin D2. Regular consumption of Chlorella may affect the iron and selenium status negatively but may impact blood lipids positively. An elevated uric acid concentration in blood and urine following the regular consumption of microalgae poses potential risks for human health.

The Efficacy of Chlorella Supplementation on Multiple Indices of Cycling Performance

This study investigated the effects of chlorella supplementation on submaximal endurance, time trial performance, lactate threshold, and power indices during a repeated sprint performance test by fourteen male trained cyclists. Participants ingested 6 g/day of chlorella or placebo for 21-days in a double-blinded randomized counter-balanced cross-over design, with a fourteen-day washout period between trials. Each completed a 2-day testing period comprising a 1-hour submaximal endurance test at 55% external power output max and a 16.1 km time trial (Day-1), followed by a lactate threshold (Dmax) and repeated sprint performance tests (3 X 20 s sprints interspersed by 4-mins) (Day-2). Heart rate (b.min-1), RER, V̇O2 (ml·kg-1·min-1), lactate and glucose (mmol/L), time (secs), power output (W/kg), and hemoglobin (g/L) were compared across conditions. Following chlorella supplementation (chlorella vs. placebo for each measurement) average lactate and heart rate were significantly lower (p < 0.05) during submaximal endurance tests (1.68 ± 0.50 mmol/L vs. 1.91 ± 0.65 mmol/L & 138 ± 11b.min-1 vs. 144 ± 10b.min-1), average power and peak power (W/kg) were significantly higher during repeated sprint bouts (9.5 ± 0.7 W/kg vs. 9.0 ± 0.7 W/kg & 12.0 ± 1.2 W/kg vs. 11.4 ± 1.4 W/kg), hemoglobin significantly increased (149.1 ± 10.3 g/L) in comparison to placebo (143.4 ± 8.7 g/L) (p = 0.05). No differences existed between conditions for all oxygen consumption values, 16.1 km time trial measures and lactate threshold tests (p > 0.05). In conclusion, chlorella may pose as an additional supplement for cyclists to consider, particularly for those cyclists who want to improve their sprinting.

Arthrospira platensis (Spirulina) fortified functional foods ameliorate iron and protein malnutrition by improving growth and modulating oxidative stress and gut microbiota in rats

The present study was aimed at developing Arthrospira platensis (Spirulina) fortified traditional foods of the Indian subcontinent, namely sattu (multigrain beverage mix) and chikki (peanut bar) and evaluating their ability to promote recovery from protein and iron deficiency anaemia (IDA) using albino Wistar rats. Addition of Spirulina (at 4% w/w Spirulina inclusion levels) enriched the protein content by 20.33% in sattu and 15.65% in chikki while the iron content was enhanced by 45% in sattu and 29.6% in chikki. In addition, the total carotenoid and polyphenol content and antioxidant capacity of the food products improved after Spirulina incorporation. Supplementation of 100 g of Spirulina fortified food products meets more than 50% of recommended dietary allowances (RDA) of protein, dietary fiber, iron and zinc for the age group 3 to 10 years of children. Spirulina contributed between 11% and 22% of RDA for protein and iron, respectively; however it contributed very negligibly to RDA of dietary fibre with respect to the nutrient requirements for the target age group. Supplementation of Spirulina fortified foods individually promoted bodyweight gain in malnourished rats and restored haemoglobin, serum protein, albumin, serum iron, and hepcidin levels and reduced the iron binding capacity indicating recovery from IDA. Spirulina supplementation ameliorated malnutrition induced oxidative stress in the liver, spleen and kidneys by reducing the lipid peroxidation and enhancing superoxide dismutase and glutathione activities. Histopathological analysis revealed that supplementation of Spirulina fortified foods reversed pathological changes such as fatty changes in the liver cells, thinning of cardiac muscle fibers and degeneration of intestinal villi. Fe-protein deficiency significantly altered the gut microflora by reducing the abundance of beneficial microbes. However, supplementation of Spirulina fortified foods improved the levels of beneficial gut microbes such as Lactobacillus reuteri and Akkermansia muciniphila while reducing the abundance of Helicobacteraceae, Enterobacteria and Clostridia. In summary, supplementation of Spirulina fortified foods promoted recovery from protein and iron deficiency indicating the bioavailability of nutrients (iron and protein) from Spirulina at par with casein and ferrous ascorbate.

Microalgae/cyanobacteria: the potential green future of vitamin B12 production

This review summarizes the available information about potential sources of vitamin B12, especially for people who follow a vegan or vegetarian diet and inhabitants of poor countries in the developing world. Cyanobacteria and microalgae approved for food purposes can play a critical role as promising and innovative sources of this vitamin. This work involves a discussion of whether the form of vitamin B12 extracted from microalgae/cyanobacteria is biologically available to humans, specifically focusing on the genera Arthrospira and Chlorella. It describes analyses of their biomass composition, cultivation requirements, and genetic properties in B12 production. Furthermore, this review discusses the function of cobalamin in microalgae and cyanobacteria themselves and the possibility of modification and cocultivation to increase the content of B12 in their biomass.

A review on plant polysaccharide based on drug delivery system for construction and application, with emphasis on traditional Chinese medicine polysaccharide

Carbohydrate polymers with unique chemical composition, molecular weight and functional chemical groups show multiple potentials in drug delivery. Most carbohydrate polymers such as plant polysaccharides exhibit advantages of biodegradability, ease of modification, low immunogenicity and low toxicity. They can be conjugated, cross-linked or functionally modified, and then used as nanocarrier materials. Polysaccharide drug delivery system can avoid the phagocytosis of the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting effective therapeutic effects. Therefore, they have been fully explored. In this paper, we reviewed the construction methods of drug delivery systems based on carbohydrate polymers (astragalus polysaccharide, angelica polysaccharide, lycium barbarum polysaccharide, ganoderma lucidum polysaccharide, bletilla polysaccharide, glycyrrhiza polysaccharide, and epimedium polysaccharides, etc). The application of polysaccharide drug delivery systems to deliver small molecule chemotherapeutic drugs, gene drugs, and metal ion drugs was also briefly introduced. At the same time, the role of the polysaccharide drug delivery system in tumor treatment, targeted therapy, and wound healing was discussed. In addition, the research of polysaccharide delivery systems based on the therapeutic efficacy of traditional Chinese medicine was also summarized and prospected.

Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination

Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field.

Effects of Tetraselmis chuii Microalgae Supplementation on Ergospirometric, Haematological and Biochemical Parameters in Amateur Soccer Players

This study aimed to analyse the effects of Tetraselmis chuii (TC) microalgae supplementation during thirty days on ergospirometric, haematological and biochemical parameters in amateur soccer players. Thirty-two amateur soccer players divided into a control group (CG; n = 16; 22.36 ± 1.36 years; 68.36 ± 3.53 kg) and a supplemented group (SG; n = 16; 22.23 ± 2.19 years; 69.30 ± 5.56 kg) participated in the double-blind study. SG ingested 200 mg of the TC per day, while CG ingested 200 mg per day of lactose powder. Supplementation was carried out for thirty days. The participants performed a maximal treadmill test until exhaustion. The ergospirometric values at different ventilatory thresholds and haematological values were obtained after the test. Heart rate decreased after supplementation with TC (p < 0.05). Oxygen pulse, relative and absolute maximum oxygen consumption increased in SG (pre vs. post; 19.04 ± 2.53 vs. 22.08 ± 2.25; 53.56 ± 3.26 vs. 56.74 ± 3.43; 3.72 ± 0.35 vs. 3.99 ± 0.25; p < 0.05). Haemoglobin and mean corpuscular haemoglobin increased in SG (pre vs. post; 15.12 ± 0.87 vs. 16.58 ± 0.74 p < 0.01; 28.03 ± 1.57 vs. 30.82 ± 1.21; p < 0.05). On the other hand, haematocrit and mean platelet volume decreased in SG (p < 0.05). TC supplementation elicited improvements in ergospirometric and haematological values in amateur soccer players. TC supplementation could be valuable for improving performance in amateur athletes.

Potential of Chlorella as a Dietary Supplement to Promote Human Health

Chlorella is a green unicellular alga that is commercially produced and distributed worldwide as a dietary supplement. Chlorella products contain numerous nutrients and vitamins, including D and B12, that are absent in plant-derived food sources. Chlorella contains larger amounts of folate and iron than other plant-derived foods. Chlorella supplementation to mammals, including humans, has been reported to exhibit various pharmacological activities, including immunomodulatory, antioxidant, antidiabetic, antihypertensive, and antihyperlipidemic activities. Meta-analysis on the effects of Chlorella supplementation on cardiovascular risk factors have suggested that it improves total cholesterol levels, low-density lipoprotein cholesterol levels, systolic blood pressure, diastolic blood pressure, and fasting blood glucose levels but not triglycerides and high-density lipoprotein cholesterol levels. These beneficial effects of Chlorella might be due to synergism between multiple nutrient and antioxidant compounds. However, information regarding the bioactive compounds in Chlorella is limited.

Alteration in iron efflux affects male sex hormone testosterone biosynthesis in a diet-induced obese rat model

This study was motivated by clinical observations that dysmetabolic iron overload syndrome (DIOS) and an androgen deficiency are common features observed in obese adult men; however, the molecular mechanism underlying the effects of DIOS on androgen deficiency remains to be elucidated. We established a DIOS animal model by feeding Sprague-Dawley rats an iron/fat-enriched diet (50% fat plus 0.25, 1, or 2 g ferric iron per kg diet) for 12 weeks to induce iron dysfunction (indicated by decreased tissue iron efflux) in obese rats. Obese rats fed an iron/fat-enriched diet showed decreased levels of testicular total Testosterone (T) and iron exporter ferroportin but increased levels of testicular iron and hepcidin, and these effects were more evident with a >1 g ferric iron per kg diet. A western blot analysis showed that an iron/fat-enriched diet triggered testicular endoplasmic reticular (ER) stress but decreased mitochondrion biogenesis proteins (PGC1α and TFAM) and T-converting proteins (StAR, CYP11A, and 17β-HSD). TUNEL staining showed that >1 g ferric iron induced apoptosis mainly in germ cells and Leydig's cells. Uncontrolled testicular iron efflux may cause mitochondrial-ER dysfunction and affect T biosynthesis. Future study targeting the testicular hepcidin-ferroportin axis may offer a therapeutic tool to alleviate testicular iron retention and mitochondrial-ER stress in Leydig's cells.

Deer blood effectively improved clinical signs of anaemia in a rodent model

Iron-deficiency anaemia (IDA) is one of the most common health problems in the world. As a type of traditional Chinese medicine, deer blood (DB) is often used to treat IDA in China. However, no scientifically designed studies with strict controls were available for the evaluation of therapeutic effects of DB on IDA. In the present study, IDA rat model was first established through feeding iron-deficient diet and then three doses of DB treatment (low, mid and high) were used to feed these rats. During the 30-day treatment period, body condition of the negative-control rats continued to decline. There was no significant difference among the groups of DB-high, positive control and overall intact control in haemoglobin concentration, haematocrit concentration and the number of red blood cells. Results showed that both groups DB-mid and DB-high showed significantly increased iron concentrations in the three organs including liver, spleen and kidney of the rats, compared with all other groups, including the positive-control group. We believe our study has opened a new avenue for the development of DB as a drug to treat IDA in clinics.