Macronutrients key to immune health for COVID-19 patients, flag experts

15 May 2023 --- Dietary proteins, omega 3 fatty acids, protein and probiotics may strengthen the immune system against the virus causing COVID-19 by decreasing inflammation and oxidative stress, Iran-based researchers suggest.

Specifically, dietary proteins may boost lung function in patients with COVID-19. Diets high in protein and amino acids also facilitate antibody production, argue the scientists.

They further note that omega 3 fatty acids could improve oxygenation, acidosis – reduced blood and body tissue alkalinity – and liver function. Moreover, probiotics have been shown to improve oxygen saturation significantly, which may enhance the survival rate in patients.

The study published in Frontiers in Nutrition reviews available research to determine the effectiveness of macronutrients and probiotics in improving immunity in patients with COVID-19. These macronutrients and microbiota are critical for general health and support the immune system’s normal function. 

Although the authors note research has reported anti-inflammatory effects of dietary fiber consumption, they add there is no evidence to suggest that carbohydrates impact the prevention or improvement of COVID-19 infection. 

Protein for antibodies 
According to the authors, data suggest diets that positively impact immune function contain adequate amounts of protein, especially glutamine, arginine and branched-chain amino acids. 

Diets high in protein and amino acids have been found to facilitate antibody production.The review highlights that sufficient protein intake is vital for antibody production, as proteins facilitate biochemical reactions and enzyme production. They act as cellular signals through hormones and cytokines, which are signaling proteins that help control inflammation and allow the immune system to mount a defense against substances that enter the body. 

The COVID-19 virus uses the angiotensin-converting enzyme 2 (ACE2) to defeat the barrier and bind to host cells. This enzyme usually binds angiotensin II, a molecule that promotes inflammation, oxidative stress and apoptosis – cell self-destruction. 

By inhibiting ACE, dietary proteins may reduce this process and protect the barriers of lungs, kidneys, heart and intestines where ACE2 is expressed. 

The study highlights evidence that asymptomatic patients and those with mild COVID-19 symptoms treated with lactoferrin protein had faster clinical recovery than untreated patients. Moreover, patients who received consistent levels of adequate protein and energy had a lower death rate than those who did not. 

Probiotics’ immune regulation 
Studies have reported that microbiota improves resistance to viruses or pathogenic attacks of respiratory mucosa, according to the review. Probiotics’ beneficial effects are likely the result of immune regulations and controlling pro- and anti-inflammatory cytokines. 

For example, clinical trials have shown that probiotics positively affect the gut and lungs by increasing regulatory T cells, improving antiviral defense and reducing pro-inflammatory cytokines during systemic and respiratory infections. 

The review refers to a study in which COVID-19 patients experienced lower diversity of gut microbiota than healthy controls. In contrast, a meta-analysis reported a positive link between probiotics consumption and reduced COVID symptoms, such as cough, headaches and diarrhea. 

The authors note the studied macronutrients and probiotics are critical to support the immune system’s normal function.Another study found that probiotic-enriched formulas reduced the duration of COVID-19 symptoms in patients, as well as viral load and lung infiltrates. At the same time, antibodies for the virus increased compared to patients that used a placebo. 

Probiotics have been investigated in several health areas, including healthy aging, immunity and beauty-from-within. 

Anti-inflammatory response with omega 3 
The authors refer to a study that linked omega 3 fatty acids from marine food to lower COVID-19 mortality rates. 

They explain that omega 3 fatty acids help to prevent the virus from entering cells by altering the phospholipid bilayer of the cell membrane. Eicosapentaenoic acid from fish and seafood sources gets incorporated into the plasma membrane, resulting in fewer pro-inflammation signals. 

Moreover, omega 3 fatty acids are critical in mediating inflammatory processes and modulating immune responses. 

The review further cites studies that show omega 3 fatty acids have antiviral effects by inhibiting influenza virus replication. Although evidence is insufficient, these outcomes suggest the compounds could improve the oxygen supply in COVID-19 patients. 

Earlier research found that maintaining high omega 3 can benefit healthy adults’ immunity and cell structure. 

By Jolanda van Hal