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18 Proven Health Benefits of L. acidophilus

Written by Biljana Novkovic, PhD | Last updated:

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Couple walking a dog L. acidophilus

L. acidophilus is a commonly used probiotic, with many health benefits. It lowers cholesterol, boosts immunity, and combats fatigue and aging. This is also a great probiotic for allergy relief. Supplementing with probiotics may not be enough however, diet plays a very important role in health and well being.

What is Lactobacillus acidophilus?

Lactobacillus acidophilus is a gram-positive lactic acid bacterium, that has been traditionally and widely used in the dairy industry, and more recently as a probiotic [1].

L. acidophilus is added to commercial yogurts and dairy formulations both for its flavor and for probiotic effect and is one of the most commonly selected Lactobacillus species for dietary use [1].

Health Benefits of L. acidophilus

1) Improves Iron Levels

Iron deficiency in young women in south India was associated with low levels of Lactobacilli [2].

Preschool children supplemented with L. acidophilus exhibited higher red blood cell status [3], and a significant reduction in the prevalence of anemia [4].

L. acidophilus increases iron bioavailability in rats [5].

2) Improves Folate and B12 Levels

Daily consumption of L. acidophilus significantly improved vitamin B12 and folate levels in children [4].

3) Is Beneficial in Diabetes

L. acidophilus preserved insulin sensitivity in men with type 2 diabetes mellitus [6].

4) Lowers Cholesterol

Daily consumption yogurt containing L. acidophilus after each dinner contributes to a significant reduction in cholesterol [7]. However, it was shown that L. acidophilus does not lower blood cholesterol in men and women with normal to borderline high cholesterol levels [8].

L. acidophilus reduces cholesterol and LDL-cholesterol in mice fed a high-fat-diet [9].

L. acidophilus lowers total blood cholesterol, LDL-cholesterol, and TAG, and total liver cholesterol and liver TAG in rats [10, 11].

5) Prevents Cardiovascular Disease

L. acidophilus consumption led to 2.4% to 3.2% reduction in blood cholesterol in clinical studies. Since every 1% reduction in serum cholesterol concentration is associated with an estimated 2% to 3% reduction in risk for coronary heart disease, regular intake of L. acidophilus has the potential of reducing the risk for coronary heart disease by 6 to 10% [12].

L. acidophilus can protect against atherosclerosis through the inhibition of intestinal cholesterol absorption in mice fed a Western diet [13].

L. acidophilus reduces cholesterol and inhibits the accumulation of lipoprotein in atherosclerotic plaques in mice [14].

L. acidophilus attenuates the development of atherosclerotic lesions in mice by reducing oxidative stress and inflammatory response [15].

6) Is Beneficial for the GI Tract

L. acidophilus Improves Intestinal Microbiota

Healthy volunteers receiving L. acidophilus and cellobiose showed increased levels of Lactobacilli, Bifidobacteria, Collinsella, and Eubacterium, while Dialister was decreased [16].

L. acidophilus increases the population of Lactobacilli and Bifidobacteria in rats [10].

L. acidophilus administered in yogurt positively shifts gut microbiota and increases intestinal Bifidobacteria in obese mice [17].

L. acidophilus increases Lactobacilli and Bifidobacteria populations, increased levels of acetic, butyric, and propionic acids, and lowers ammonium in a human microbiota stimulator [18].

L. acidophilus May Ameliorate Ulcers

L. acidophilus promotes gastric ulcer healing in rats [19].

L. acidophilus May Ameliorate GI Infections

L. acidophilus alleviates E. coli infection in mice [20].

L. acidophilus inhibits the growth of C. difficile, a pathogenic bacterium that causes antibiotic-associated diarrhea [21] and inhibits the growth of Salmonella enterica in mice, especially when administered after the infection [22].

L. acidophilus is Beneficial in GI Inflammation

L. acidophilus counteracts inflammation in intestinal epithelial cells [23].

Treatment with L. acidophilus significantly increased butyrate uptake in intestinal epithelial cells. Butyrate plays beneficial roles serving as a primary fuel, ameliorating mucosal inflammation, and stimulating salt absorption [24].

L. acidophilus has a protective effect on the development of necrotizing enterocolitis (NEC) in rats [25].

L. acidophilus improves inflammatory and functional aspects of intestinal mucositis caused by chemotherapy in mice [26].

L. acidophilus protects against colitis-induced weight loss and increases beneficial Lactobacilli and Bifidobacteria in the distal colon in mice. [27]

L. acidophilus reduces intestinal inflammation following infection in newborn mice [28].

L. acidophilus is Beneficial in Antibiotic Therapy

L. acidophilus administered with amoxicillin/clavulanate was associated with a significant decrease in patient complaints of GI side effects and yeast superinfection [29].

L. acidophilus Attenuates Diarrhea

Some trials found no beneficial effect on the prevention of travelers’ diarrhea [30] or acute diarrhea in children [31].

Other studies show that heat-killed L. acidophilus markedly improved symptoms in patients with chronic diarrhea [32], L. acidophilus reduced the duration of diarrhea in hospitalized, but not outpatient, children [33], and ameliorated both rotavirus-positive diarrhea [34] and nonrotavirus diarrhea in children [35].

L. acidophilus attenuates diarrhea in mice [36].

L. acidophilus is Beneficial in IBS

L. acidophilus reduced abdominal pain and discomfort in patients with irritable bowel syndrome (IBS) [37, 38].

7) Combats H. pylori

L. acidophilus improves intestinal inflammation caused by H. pylori [39] and decreases the viability of H. pylori and increases the eradication rate in infected patients [40].

8) Is Beneficial for the Liver

L. acidophilus improves blood ammonia and cognitive function in patients with minimal hepatic encephalopathy (MHE) and reduces the risk of developing overt encephalopathy [41].

9) Boosts Immunity

L. acidophilus enhances natural and acquired immunity in healthy mice [42].

L. acidophilus May Combat Viruses

Both live and non-live L. acidophilus have protective effects against influenza virus (H1N1) infection in mice [43].

L. acidophilus May Combat Bacteria

L. acidophilus can effectively prevent bacteria-induced colitis by limiting infection and promoting mucosal protective regulatory immune responses in mice [44].

L. acidophilus suppressed all of the 74 gram-negative and 16 of gram-positive bacteria found in burn wounds, that can cause burn wound infections [45].

L. acidophilus may reduce mutant Streptococcus in dental plaque, and may decrease the cariogenic potential of oral streptococci [46].

10) Is Beneficial in Aging

L. acidophilus increases Bifidobacteria levels and beneficially changes microbiota in elderly subjects [47].

Dahi containing L. acidophilus was effective in reversing age-related immune function decline in mice [48].

Dahi containing L. acidophilus combats oxidative stress and molecular alterations associated with aging in mice [49].

11) Combats Fatigue

L. acidophilus reverses immune defects in fatigued athletes [50] and decreases chronic fatigue following exercise and attenuated stress in rats [51].

12) Alleviates Inflammation

L. acidophilus alleviates inflammation in human intestinal epithelial cells [52] and decreases the transcriptional activity of NF-κB and inhibits proinflammatory cytokines [53].

13) May Ameliorate Arthritis

L. acidophilus decreases arthritis symptoms and maintains normal histology of reproductive organs in rats [54].

L. acidophilus showed effects comparable to the drug indomethacin, in decreasing organ damage associated with arthritis in rats. This probiotic down-regulated pro-inflammatory and up-regulated anti-inflammatory cytokines [55].

14) Mitigates Atopic Dermatitis

L. acidophilus suppresses Th2-dominant inflammation by activating regulatory T cells and Th1 helper T cells in atopic dermatitis [56].

Long-term oral administration of L. acidophilus significantly restored Th1/Th2 balance and ameliorated the symptoms of atopic dermatitis in children [57].

Prolonged ingestion of L. acidophilus significantly decreased eczema area and severity index in patients with adult atopic dermatitis [56, 58]. The probiotic also suppressed scratching behavior [56].

L. acidophilus suppresses ear swelling, scratching behavior and other dermatitis-like symptoms in mice [59, 60].

15) Is Beneficial in Allergy

L. acidophilus alleviated the allergic symptoms in patients with Japanese cedar pollinosis [61, 62].

L. acidophilus alleviates the symptoms in patients with perennial allergic rhinitis [63].

L. acidophilus may improve lactose digestion and tolerance [64, 65].

L. acidophilus suppresses hypersensitivity, attenuates the numbers of inflammatory cells and inhibits Th17 and IgE production in mice with allergy [66].

L. acidophilus increases the number of Treg cells to suppress the progression of allergic contact dermatitis in mice [67] and suppresses nasal symptoms and IgE in allergic mice [61, 68].

16) May Alleviate Pain

Oral administration of L. acidophilus induces the expression of mu-opioid and cannabinoid receptors in intestinal epithelial cells and mediates analgesic functions in the gut similar to the effects of morphine [69].

17) Is Beneficial in Urogenital Infections

L. acidophilus maintains low pH and increases human vaginal epithelial cell viability [70].

Daily ingestion yogurt, enriched with L. acidophilus may reduce the episodes of bacterial vaginosis [71].

Treatment of patients with bacterial vaginosis with L. acidophilus contributed to the restoration of a normal vaginal environment [72].

18) Combats Cancer

L. acidophilus is toxic to human gastric carcinoma, colon carcinoma, and breast cancer cells [73, 74].

Daily oral administration of L. acidophilus suppressed colon tumor incidence, tumor multiplicity, and reduced tumor size in mice [75].

Oral administration of L. acidophilus increased survival [76], decreased tumor growth and increased lymphocyte proliferation in mice with breast tumors [77].

L. acidophilus reduced tumor volume growth by 50.3 %, reduced the severity of colonic carcinogenesis, and enhanced cancer cell death in mice [78].

L. acidophilus decreased carcinogenic changes in the colon in rats [79].

L. acidophilus alters the cytokine production in tumor-bearing mice into a Th1 protective pattern, favorable to anti-tumor immunity [77].


In Infection

  • Enhances natural killer cell (NK) activity [43, 80].
  • Decreases NF-κB [81, 39] and increases IL-8 [39].
  • In influenza, L. acidophilus increases eotaxin, CSF1, IL-1β, RANTES, and IFN -α in the lung, and increases IL-17 in the intestine [43].
  • Can upregulate IL-1α, IL-1β, CCL2, and CCL20, and activate TLR2 in intestinal epithelial cells [82].

In Fatigue

  • Increased the secretion of IFNγ from T-cells in fatigued athletes [50].

In Inflammation

In Allergies

  • Suppresses IgE [59, 61], IL-4 [84,85], IL-17A and IL-6 [66,66].
  • Increases TGF-β and IgA [84, 66, 66, 67].
  • Both increases and decreases IFN-γ [84, 85] and IL-10 [66, 67].
  • Increases CD25 and FOXP3 [66] and decreases RORγt [66].
  • Significantly increases CD4(+)CD25(+)Foxp3(+) T cells [67], decreases the proliferation of CD4(+) T cells stimulated with antigen, and kills antigen-stimulated T cells [85].

In Aging

  • Improves peritoneal macrophage functions, stimulates NO and IL-6, and inhibits PGE2 [48].
  • Improves lymphocyte functions and stimulates IL-2 [48].
  • Increases catalase (CAT) activity [49].
  • Reverses age-related decline in PPARα, SMP-30, and klotho [49].

In Cancer

  • Alters the cytokine production in tumor into a Th1 protective pattern, favorable to anti-tumor immunity [77, 76].
  • Inhibits the expressions of genes involved in tumor angiogenesis and survival VEGF and HIF-1α [74].
  • It upregulates TIMP-3, HIF-2α, HO-1, and PAI-1 [74].
  • It increases IFN-γ and decreases IL-4 [76].


L. acidophilus is generally well tolerated. However, the use of probiotics should be avoided in patients with organ failure, immunocompromised status, and dysfunctional gut barrier mechanisms, where it can lead to infections [86].

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About the Author

Biljana Novkovic

Biljana received her PhD from Hokkaido University.
Before joining SelfHacked, she was a research scientist with extensive field and laboratory experience. She spent 4 years reviewing the scientific literature on supplements, lab tests and other areas of health sciences. She is passionate about releasing the most accurate science & health information available on topics, and she's meticulous when writing and reviewing articles to make sure the science is sound. She believes that SelfHacked has the best science that is also layperson-friendly on the web.

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