Bacterial Infections

Enhancing Your Immune System While Fighting Bacteria

The nutrients vitamin A, beta-carotene, folic acid, vitamin B12, vitamin C, vitamin D, riboflavin, iron, copper, zinc, and selenium have both antioxidant activity and immunomodulating functions that affect the course and outcome of bacterial infections (Bhaskaram P 2001; Meydani SN et al 2001; Murray et al 1997). In general, people taking multivitamin and multimineral supplements report significantly fewer infectious illnesses. In one small study, efficacy was highest in individuals with type 2 diabetes (Barringer TA et al 2003).

Glutamine. Glutamine helps build and maintain muscles and modulate pH and contributes to a healthy digestive system (MacKay D et al 2003). It is also an important precursor to glutathione, a natural antioxidant. Glutamine has been shown to help boost immune function through white blood cell respiration and production of messenger chemicals used by the immune system (Bistrian BR 2004).

Vitamin A. Low levels of vitamin A have been associated with increased susceptibility to bacterial infection, and vitamin A supplementation has been suggested to decrease days of work lost to infection (Aukrust P et al 2000; Barringer TA et al 2003; Bhaskaram P 2001). Vitamin A appears to be important in mucosal immune responses in the respiratory and gastrointestinal tracts (Cui D et al 2000). The effect may be primarily from stabilizing the membranes of mucosal cells and enhancing white blood cell function (Molina EL et al 1996). Vitamin A has been studied in dosages up to 75,000 international units (IU) per day for up to 12 months in the context of skin cancer with no appreciable toxicity (Alberts D et al 2004).

Vitamin E. Vitamin E improves immune function in the elderly. Supplementation with vitamin E (alpha-tocopherol) has been documented to increase levels of anti-inflammatory chemicals and decrease levels of proinflammatory proteins (Meydani SN et al 2001). Vitamin E enhances the immune system through its ability to protect immune cells from free-radical attack, which preserves membrane integrity and fluidity (Tengerdy RP 1990).

Zinc. Many studies have shown that zinc deficiency is associated with impaired immune function (Bogden JD 2004; Cuevas LE et al 2005; Cunningham-Rundles S et al 2000; Stefanidou M et al 2005). A combination of zinc and selenium may enhance immunity and protect against infections, especially in the elderly. A review article of published studies showed that elderly individuals taking modest doses of a multivitamin and multimineral dietary supplement containing zinc and selenium had fewer days on antibiotics and fewer infections than counterparts who did not take zinc-containing multivitamins or supplements (Chandra RK 1992).

Garlic. Crushed garlic has potent antibacterial effects (Ankri S et al 1999; Cutler RR et al 2004; Jonkers D et al 1999; Sovova M et al 2002). It fights infection by enhancing immune cell activity and inhibiting bacteria and other microorganisms (Craig WJ 1997; Harris JC et al 2001). The compound in garlic that produces antibacterial activity is known as allicin (Ankri S et al 1999; Sovova M et al 2002). Allicin is released when intact cells of a garlic clove are cut or crushed. There is evidence that garlic is effective against antibiotic-resistant strains of Staphylococcus species, pneumonia-causing bacteria, and antibiotic-resistant strains of H. pylori (Dikasso D et al 2002; Sivam GP 2001; Tsao SM et al 2003).

Goldenseal. Goldenseal (a member of the buttercup family) has been used topically to treat eye and skin irritations and orally to treat infections (O'Hara M et al 1998). Berberine, the main active ingredient in goldenseal, prevents bacteria from adhering to epithelial cells (Sun D et al 1988), inhibits the intestinal secretory response of cholera and E. coli toxins, and normalizes intestinal mucous membranes after damage from cholera (Sack RB et al 1982).

Licorice. Licorice is derived from the root of the Glycyrrhiza species. Glycyrrhizin is converted by intestinal flora to glycyrrhetinic acid, which has immunomodulating activity. In laboratory studies, glycyrrhetinic acid has demonstrated powerful effects against H. pylori gastritis and ulcers (Chung JG 1998; Krausse R et al 2004). Studies have shown that, in humans, adverse effects begin at daily dosages of 100 mg (Stormer FC et al 1993).

Lactoferrin. Lactoferrin, a component of whey, increases good microflora (such as Bifidobacterium bifidum) and decreases bad bacteria, resulting in a desirable intestinal flora environment that is essential for optimal health, immunity, and disease resistance.

Other organisms inhibited by lactoferrin include gram-positive and gram-negative bacteria, yeasts, and some intestinal parasites such as Vibrio cholerae, E. coli (Haversen LA et al 2000), Shigella flexneri, S. epidermidis, P. aeruginosa, and Candida albicans (Baldi A et al 2005; Griffiths EA et al 2003; Kuwata H et al 1998; Nikolaev AA et al 2004).

Lactoferrin may be especially useful as an adjuvant therapy for antibiotics. One study looked at the synergistic effect between lactoferrin and vancomycin. Researchers found that lactoferrin lowered vancomycin-resistance in some bacteria (Leitch EC et al 2001).

Probiotics. Probiotics are bacterial cultures contained in yogurt, buttermilk, cheese, kefir, and sauerkraut, or in dietary supplements that contain friendly bacteria (such as Lactobacillus, Bifidobacterium, Eubacterium, and Propionibacterium species) normally present on skin and in vaginal, urinary, and intestinal tracts. These bacteria are essential to the proper function of the vaginal, urinary, and digestive tracts (Bengmark S 1998; Cunningham-Rundles S et al 2000; Dani C et al 2002).

Probiotics assist immune function by inhibiting harmful bacterial growth, promoting good digestion, maintaining proper pH, and enhancing immune function (Perdigon G et al 1995). Probiotics produce bacteria-inhibiting substances (natural antibiotics) and prevent harmful bacteria from attaching to vaginal, urinary, and intestinal tract mucosal linings (Ochmanski W et al 1999; Vaughan EE et al 1999). Probiotics have demonstrated In vitro ability to suppress H. pylori (Cremonini F et al 2001; Drouin E 1999; Felley C et al 2003; Johnson-Henry KC et al 2004; Wang KY et al 2004). They may be useful in preventing acute infectious diarrhea (Marignani M et al 2004), urinary tract infections (Kontiokari T et al 2003; Reid G 2002), and restoring vaginal flora (Andreeva P et al 2002).

Antibiotics often destroy friendly bacteria on skin and in urinary, vaginal, and intestinal tracts. Probiotics can be used to recolonize and restore natural floral balance in organ and body systems after antibiotic treatment (Fooks LJ et al 2002; Guarner F et al 2003; Shi HN et al 2004).

Tea catechins. Tea (black, green, or oolong) is a good source of free radical-scavenging antioxidants (Trevisanato SI et al 2000). Other infection-fighting chemicals were heightened in cells of tea drinkers, leading researchers to conclude that drinking tea primed the immune system to fight infection (Bukowski JF et al 1999; Kamath AB et al 2003).

These results have been borne out in many clinical studies. Elements of tea, called catechins, have been widely studied for their ability to prevent bacterial infection. One such study examined catechins' ability to prevent infection in the prostate gland in rats. This condition, known as chronic bacterial prostatitis, is extremely common in men. Researchers found that tea catechins were able to reduce both bacterial growth and inflammation in the rats' prostate glands. Morever, the catechins worked well as an adjuvant therapy for ciprofloxacin, the standard antibiotic treatment for this condition. Researchers suggested that tea catechins, which have shown additional antibacterial effects and synergistic properties with antibiotics, be considered to help manage chronic bacterial prostatitis (Lee YS et al 2005).

In another interesting study, researchers infused plastic film with tea catechins, then tested this surface for antibacterial properties. They found that the catechin-infused film was significantly resistant to bacteria such as E. coli and suggested that implants and catheters made from catechin-infused plastic might be able to help reduce infection during invasive procedures (Maeyama R et al 2005).

Catechins are thought to boost immunity by enhancing resistance to infection and selectively modulating the formation of cytokines, which are associated with inflammation, among other things. Researchers have also hypothesized that hydrogen peroxide generated by the catechins may also be responsible for its antibacterial properties (Arakawa H et al 2004). In a laboratory study of immune cells taken from heavy smokers, tea catechins were shown to help the immune cells recover their function (Yamamoto Y et al 2004).