Probiotics and Bacteriotherapy Reviews

Journal Citation:

d’Ettorre G, Ceccarelli G, Giustini N, Serafino S, Calantone N, De Girolamo G, Bianchi L, Bellelli V, Ascoli-Bartoli T, Marcellini S, Turriziani O, Brenchley JM, Vullo V. Probiotics Reduce Inflammation in Antiretroviral Treated, HIV-Infected Individuals: Results of the “Probio-HIV” Clinical Trial. PLoS One. 2015 Sep 16;10(9):e0137200.

Published Abstract

BACKGROUND:  HIV infection results in damage to the gastrointestinal (GI) tract, microbial translocation and immune activation. These are not completely normalized with combined antiretroviral therapy (cART). Moreover, increate morbidity and mortality of cART-treated HIV-infected individuals is associated with inflammation. METHODS:  In order to enhance GI tract immunity, we recruited and treated 20 HIV-infected humans with cART supplemented with probiotics and followed inflammation and immunological parameters (clinical trial number NCT02164344). 11 HIV seronegative subjects were included as control group. The enumeration of CD4+, CD8+, CD38+ and HLA-DR+ lymphocytes were evaluated on peripheral blood; HIV-RNA levels, sCD14, d-dimer, C-reactive protein (CRP) high sensitivity C-reactive protein (hsCRP), IL-6 and Lipopolysaccharide Binding Protein (LBP) were assayed on plasma. RESULTS:  We observe that cART does not normalize the levels of immune activation in HIV positive patients anyway inflammation and markers of microbial translocation were significantly reduced with probiotic supplementation. Patients show a clear and statistically significant reduction in the levels of immune activation on CD4 T-lymphocytes, for both markers CD38 and HLA-DR and their simultaneous expression, LBP and hsCRP plasma levels after probiotic diet supplementation settling to values comparable to controls. CONCLUSIONS:  Supplementing cART with probiotics in HIV-infected individuals may improve GI tract immunity and there by mitigate inflammatory sequelae, ultimately improving prognosis.

Introduction & Background to Study

Infection with the retrovirus known as Human Immunodeficiency Virus (HIV) often begins insidiously as a “cold” or “flu.” Gastrointestinal symptoms like diarrhea and abdominal distress often follow, as the virus multiplies in the white blood cells, which are incredibly numerous in the lining of the intestinal tract. It is no wonder, then, that the early stages of HIV infection are associated with a perturbation (“dysbiosis”) of the GI tract microbiome, with reduced numbers of bifidobacteria and lactobacillus species, along with increased numbers of potentially pathogenic proteobacteria species. As the retroviral disease advances, so does the destruction of the cellular immune system, until we can no longer defend ourselves from the microbial world outside or within us, nor can we effectively find and destroy those mutated cells that we call cancers.

The development of antiretroviral therapy (ART) – and in particular, the use of multiple agents simultaneously to create a highly active or combined antiretroviral therapy “cocktail” (HAART or cART) – have effectively converted HIV infection from a rapidly fatal infection into a chronic disease. Still, patients treated with cART have a shorter life span than non-infected persons, and they have a variety of complications that are not directly attributable to the drugs themselves. These complications include gastrointestinal, hepatic, renal, cardiac, and neurological systems. One mechanism that may play a role in at least some of these disorders may be inflammation, for increased inflammation and immune activation have been common in HIV positive individuals, even when the virus appears completely suppressed by appropriate therapy.

HIV-positive persons – even those with completely “controlled infection” – have higher levels of activated T cells, inflammatory monocytes and pro-inflammatory cytokines than seronegative individuals. Possible causes include ongoing HIV replication at low levels (less than what can be detected by our current technology), the presence of coinfections, and microbial translocation.

The authors of this paper Hypothesized that, if microbial translocation is a cause, and if some of the microbes responsible were those in the dysbiotic gut, then probiotics might be able to control or reverse the inflammatory state. To that end, they provided HIV-positive subjects with both cART and a probiotic supplement for 48 weeks, and monitored immune function and activation status.

Materials & Methods

Study subjects: Subjects were eligible for the study if they were HIV-positive but did not have a diagnosis of AIDS nor nor any current acute infection. They had to be on their first cART regimen with good viral control (viral load less than 37 copies/ml). “Control” subjects were selected from among the HIV-negative community, though beyond that, the precise selection criteria were not described. 

Intervention: The HIV-positive subjects were given twice daily dietary supplements with 1 g packets containing Streptococcus salivarius ssp. Termophilus, Bifidobacteria (represented by B. breve, B. infantis and B. longum), Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus delbrueckii ssp. Bulgaricus, and Streptococcus faecium for 48 weeks. The HIV-negative subjects were not given any such supplements.

Data collection: At the beginning of the study and again at the end (48 weeks later), blood tests were drawn to evaluate inflammatory and immunological parameters. Commercially available enzyme-linked immunosorbent assays (ELISAs) were used to quantify plasma levels of soluble CD14 (sCD14), D-dimer, C-reactive protein (CRP), high sensitivity CRP (hsCRP), interleukin 6 (IL-6) and lipopolysaccharide binding protein (LBP). White blood cells (CD4+, CD8+, CD38+ and HLA-DR+ lymphocytes) were measured in the peripheral blood. HIV rna was measured at the beginning and end of the study; the limit of detection was 1 copy/ml. Additionally, a self-administered questionnaire solicited demographic information, history of prior probiotic use, adherence to the study interventions, and bowel symptoms.

Study Results

A total of 20 HIV-positive subjects were enrolled: 17 men and 3 women, median age was 54 years (range 27–72). All subjects were on cART from at least 3 years (median 12,5 years; range 3–20) and had a median of CD4+ T cell count of 542 cells/μl. (range 285–1402) and HIV RNA of <40 copies/mL at the time of enrolment. Seven women and 4 men comprised the HIV-negative control arm, with an average age of 43 (ranging from 28 to 73 years). Only 29% of patients certified that they had taken lactic acid bacteria in the past, and only a third of the sample regularly consumed yogurt.

CD4+ T cells among HIV+ subjects were lower than for seronegative subjects, consistent with reports in the literature. Also predictably, immune activation was higher in HIV+ subjects than in healthy controls.

Some markers of immune activation decreased significantly over the 48 weeks of probiotic treatment, approaching the lower level of the control group by the end of the study. A small increase in CD4 numbers and percentages was seen over the 48 weeks of probiotics, but this was not considered statistically significant (p = 0.065).

Regarding subjective symptoms of gastrointestinal health, all subjects treated with probiotics reported substantial improvement in digestion, reduced intestinal bloating, reduced episodes of acute diarrhea or constipation.

Probiotics were associated with no adverse events and no drop-outs from the study. The cost of probiotics (borne by the study subjects themselves) was described by all subjects as “too expensive.”

Author’s Conclusions

The authors concluded that “Supplementing cART with probiotics in HIV-infected individuals may improve GI tract immunity and there by mitigate inflammatory sequelae, ultimately improving prognosis . . . . However, the suggestions provided by this pilot study and other researches on the topic are still preliminary and fragmentary to draw any firm conclusions. Instead they represent an

important incentive to justify larger studies to assess whether probiotic administration truly could decrease inflammation and improve the prognosis of cART-treated, HIV-infected, individuals . . . . In conclusion current and emerging studies support the concept that probiotic bacteria can provide specific benefit in HIV infected patients during antiretroviral treatment by improvement of the microbiota and reducing mucosal and systemic inflammation.”

Reviewer’s Conclusions

Probiotics were clearly associated with a better sense of gastrointestinal health. There was also a suggestion that probiotics might decrease the immune activation seen in HIV+ patients. But because the study design called for no control arm of HIV+ subjects who did NOT receive probiotics, we can not deduce with any certainty that the probiotics were responsible for these outcomes. In addition to an HIV+ control arm, I would suggest that any follow-up study examine the immunological parameters more frequently than once every two years (for example, check at 3 months, 6 months, and every 6 months thereafter) just in case there is an effect that occurs early but then wanes.

This reviewer agrees with the authors that probiotics just may decrease the inflammatory state seen in chronic HIV infection. This pilot study deserves to be followed by a larger and better controlled study, and hopefully they are already on it.