Nutrients

888 KiB

Open AccessReview

Effect of Probiotic Bacteria on Microbial Host Defense, Growth, and Immune Function in Human Immunodeficiency Virus Type-1 Infection

by Susanna Cunningham-Rundles, Siv Ahrné, Rosemary Johann-Liang, Rachel Abuav, Ann-Margaret Dunn-Navarra, Claudia Grassey, Stig Bengmark and Joseph S. Cervia

Nutrients 2011, 3(12), 1042-1070; https://doi.org/10.3390/nu3121042 - 19 Dec 2011

Cited by 83 | Viewed by 14523

Abstract

The hypothesis that probiotic administration protects the gut surface and could delay progression of Human Immunodeficiency Virus type1 (HIV-1) infection to the Acquired Immunodeficiency Syndrome (AIDS) was proposed in 1995. Over the last five years, new studies have clarified the significance of HIV-1 infection of the gut associated lymphoid tissue (GALT) for subsequent alterations in the microflora and breakdown of the gut mucosal barrier leading to pathogenesis and development of AIDS. Current studies show that loss of gut CD4+ Th17 cells, which differentiate in response to normal microflora, occurs early in HIV-1 disease. Microbial translocation and suppression of the T regulatory (Treg) cell response is associated with chronic immune activation and inflammation. Combinations of probiotic bacteria which upregulate Treg activation have shown promise in suppressing pro inflammatory immune response in models of autoimmunity including inflammatory bowel disease and provide a rationale for use of probiotics in HIV-1/AIDS. Disturbance of the microbiota early in HIV-1 infection leads to greater dominance of potential pathogens, reducing levels of bifidobacteria and lactobacillus species and increasing mucosal inflammation. The interaction of chronic or recurrent infections, and immune activation contributes to nutritional deficiencies that have lasting consequences especially in the HIV-1 infected child. While effective anti-retroviral therapy (ART) has enhanced survival, wasting is still an independent predictor of survival and a major presenting symptom. Congenital exposure to HIV-1 is a risk factor for growth delay in both infected and non-infected infants. Nutritional intervention after 6 months of age appears to be largely ineffective. A meta analysis of randomized, controlled clinical trials of infant formulae supplemented with Bifidobacterium lactis showed that weight gain was significantly greater in infants who received B. lactis compared to formula alone. Pilot studies have shown that probiotic bacteria given as a supplement have improved growth and protected against loss of CD4+ T cells. The recognition that normal bacterial flora prime neonatal immune response and that abnormal flora have a profound impact on metabolism has generated insight into potential mechanisms of gut dysfunction in many settings including HIV-1 infection. As discussed here, current and emerging studies support the concept that probiotic bacteria can provide specific benefit in HIV-1 infection. Probiotic bacteria have proven active against bacterial vaginosis in HIV-1 positive women and have enhanced growth in infants with congenital HIV-1 infection. Probiotic bacteria may stabilize CD4+ T cell numbers in HIV-1 infected children and are likely to have protective effects against inflammation and chronic immune activation of the gastrointestinal immune system. Full article

(This article belongs to the Special Issue Probiotics and Nutrition)

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205 KiB

Open AccessReview

The Potential Role of Vitamin D Enhanced Foods in Improving Vitamin D Status

by Louise O’Mahony, Magdalena Stepien, Michael J. Gibney, Anne P. Nugent and Lorraine Brennan

Nutrients 2011, 3(12), 1023-1041; https://doi.org/10.3390/nu3121023 - 16 Dec 2011

Cited by 104 | Viewed by 12032

Abstract

Low vitamin D intake and status have been reported worldwide and many studies have suggested that this low status may be involved in the development of several chronic diseases. There are a limited number of natural dietary sources of vitamin D leading to a real need for alternatives to improve dietary intake. Enhancement of foods with vitamin D is a possible mode for ensuring increased consumption and thus improved vitamin D status. The present review examines studies investigating effects of vitamin D enhanced foods in humans and the feasibility of the approach is discussed. Full article

(This article belongs to the Special Issue Vitamin D)

237 KiB

Open AccessReview

A Carotenoid Health Index Based on Plasma Carotenoids and Health Outcomes

by Michael S. Donaldson

Nutrients 2011, 3(12), 1003-1022; https://doi.org/10.3390/nu3121003 - 08 Dec 2011

Cited by 40 | Viewed by 11039

Abstract

While there have been many studies on health outcomes that have included measurements of plasma carotenoids, this data has not been reviewed and assembled into a useful form. In this review sixty-two studies of plasma carotenoids and health outcomes, mostly prospective cohort studies or population-based case-control studies, are analyzed together to establish a carotenoid health index. Five cutoff points are established across the percentiles of carotenoid concentrations in populations, from the tenth to ninetieth percentile. The cutoff points (mean ± standard error of the mean) are 1.11 ± 0.08, 1.47 ± 0.08, 1.89 ± 0.08, 2.52 ± 0.13, and 3.07 ± 0.20 µM. For all cause mortality there seems to be a low threshold effect with protection above every cutoff point but the lowest. But for metabolic syndrome and cancer outcomes there tends to be significant positive health outcomes only above the higher cutoff points, perhaps as a triage effect. Based on this data a carotenoid health index is proposed with risk categories as follows: very high risk: < 1 µM, high risk: 1–1.5 µM, moderate risk: 1.5–2.5 µM, low risk: 2.5–4 µM, and very low risk: > 4 µM. Over 95 percent of the USA population falls into the moderate or high risk category of the carotenoid health index. Full article

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Nutrients, Volume 3, Issue 12 (December 2011) – 3 articles , Pages 1003-1070

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