Oral serum-derived bovine immunoglobulin improves duodenal immune reconstitution and absorption function in patients with HIV enteropathy

Dietary requirement for serum-derived bovine immunoglobulins in the clinical management of patients with enteropathy

A variety of human disease conditions are associated with chronic intestinal disorders or enteropathies that are characterized by intestinal inflammation, increased gut permeability, and reduced capacity to absorb nutrients. Such disruptions in the homeostasis of the gastrointestinal (GI) tract can lead to symptoms of abdominal pain and discomfort, bloating, abnormal bowel function, and malabsorption of nutrients. While significant advances have been made in understanding the factors that influence the complex and fragile balance between the gut microbiota, intestinal epithelial cell integrity, and the underlying immune system, effective therapies for restoring intestinal balance during enteropathy are still not available. Numerous studies have demonstrated the ability of oral immunoglobulins to improve weight gain, support gut barrier function, and reduce the severity of enteropathy in animals. More recently, studies in humans provide evidence that serum-derived bovine immunoglobulin/protein isolate is safe and improves nutritional status and GI symptoms in patients with enteropathy associated with irritable bowel syndrome or infection with the human immunodeficiency virus. This review summarizes studies showing the impact of enteropathy on nutritional status and how specially formulated bovine immunoglobulins may help restore intestinal homeostasis and nutritional status in patients with specific enteropathies. Such protein preparations may provide distinct nutritional support required for the dietary management of patients who, because of therapeutic or chronic medical needs, have limited or impaired capacity to digest, absorb, or metabolize ordinary foodstuffs or certain nutrients, or other special medically determined nutrient requirements that cannot be satisfied by changes to the normal diet alone.

Noninfectious Diarrhea in HIV Seropositive Individuals: a Review of Prevalence Rates, Etiology, and Management in the Era of Combination Antiretroviral Therapy

Introduction

Diarrhea poses a substantial burden for patients with human immunodeficiency virus (HIV), negatively impacting quality-of-life (QoL) and adherence to antiretroviral therapy. During the combination antiretroviral therapy (cART) era, as incidence of opportunistic infection as a cause of diarrhea decreased, incidence of noninfectious diarrhea (including diarrhea as an adverse event [AE] of cART and HIV enteropathy) increased proportionately. A literature search was conducted for information on prevalence, etiology, and treatment options for noninfectious diarrhea in patients with HIV.

Results

For marketed antiretroviral therapies, up to 28% of patients live with >4 loose or watery stools per day. The US Food and Drug Administration (FDA) does not require pharmaceutical manufacturers to include, within approved prescribing information, prevalence rates for all grades of diarrhea. Traditionally, noninfectious diarrhea management focused on avoiding use of diarrhea-associated cART; symptom management (nonpharmacologic and/or pharmacologic); and, as a last resort, changing cART. Examining the evidence upon which this approach is based reveals that most strategies rely upon anecdotal information and case reports. This review summarizes the literature and updates clinicians on the most recent options for management of noninfectious diarrhea in patients with HIV.

Conclusion

Diarrhea in patients with HIV is a significant unmet clinical need that contributes to worsening QoL and complicates medical management. Approaching management using a stepwise method of nonpharmacologic (diet), nonprescription (over-the-counter) and, finally, prescription agent changes (modification of cART or addition of an evidence-based antidiarrheal) appears reasonable, despite a lack of clear scientific evidence to support the initial two steps of this approach. If diet modifications, including psyllium and fiber introduction, fail to resolve noninfectious diarrhea in patients with HIV, loperamide followed by crofelemer should be considered. Clinicians are encouraged to review the most recent literature, not rely upon prescribing information. Continued vigilance by HIV providers to the presence of gastrointestinal AEs, even in patients taking the most recently approved antiretroviral agents, is warranted. Additional research is justified in identifying the etiology and management of HIV-associated diarrhea in patients on successful cART regimens.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-014-0047-5) contains supplementary material, which is available to authorized users.

A 12 week longitudinal study of microbial translocation and systemic inflammation in undernourished HIV-infected Zambians initiating antiretroviral therapy

Background

Undernourished, HIV-infected adults in sub-Saharan Africa have high levels of systemic inflammation, which is a risk factor for mortality and other adverse health outcomes. We hypothesized that microbial translocation, due to the deleterious effects of HIV and poor nutrition on intestinal defenses and mucosal integrity, contributes to heightened systemic inflammation in this population, and reductions in inflammation on antiretroviral therapy (ART) accompany reductions in translocation.

Methods

HIV-infected, Zambian adults with a body mass index <18.5 kg/m² were recruited for a pilot study to assess the relationships between microbial translocation and systemic inflammation over the first 12 weeks of ART. To assess microbial translocation we measured serum lipopolysaccharide binding protein (LBP), endotoxin core IgG and IgM, and soluble CD14, and to assess intestinal permeability we measured the urinary excretion of an oral lactulose dose normalized to urinary creatinine (Lac/Cr ratio). Linear mixed models were used to assess within-patient changes in these markers relative to serum C-reactive protein (CRP), tumor necrosis factor-α receptor 1 (TNF-α R1), and soluble CD163 over 12 weeks, in addition to relationships between variables independent of time point and adjusted for age, sex, and CD4+ count.

Results

Thirty-three participants had data from recruitment and at 12 weeks: 55% were male, median age was 36 years, and median baseline CD4+ count was 224 cells/μl. Over the first 12 weeks of ART, there were significant decreases in serum levels of LBP (median change -8.7 μg/ml, p = 0.01), TNF-α receptor 1 (-0.31 ng/ml, p < 0.01), and CRP (-3.5 mg/l, p = 0.02). The change in soluble CD14 level over 12 weeks was positively associated with the change in CRP (p < 0.01) and soluble CD163 (p < 0.01). Pooling data at baseline and 12 weeks, serum LBP was positively associated with CRP (p = 0.01), while endotoxin core IgM was inversely associated with CRP (p = 0.01) and TNF-α receptor 1 (p = 0.04). The Lac/Cr ratio was not associated with any serum biomarkers.

Conclusions

In undernourished HIV-infected adults in Zambia, biomarkers of increased microbial translocation are associated with high levels of systemic inflammation before and after initiation of ART, suggesting that impaired gut immune defenses contribute to innate immune activation in this population.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-521) contains supplementary material, which is available to authorized users.

Bovine immunoglobulin protein isolates for the nutritional management of enteropathy

The gastrointestinal tract is responsible for a multitude of digestive and immune functions which depend upon the balanced interaction of the intestinal microbiota, diet, gut barrier function, and mucosal immune response. Disruptions in one or more of these factors can lead to intestinal disorders or enteropathies which are characterized by intestinal inflammation, increased gut permeability, and reduced capacity to absorb nutrients. Enteropathy is frequently associated with human immunodeficiency virus (HIV) infection, inflammatory bowel disease, autoimmune enteropathy, radiation enteritis, and irritable bowel syndrome (IBS), where pathologic changes in the intestinal tract lead to abdominal discomfort, bloating, abnormal bowel function (e.g., diarrhea, urgency, constipation and malabsorption). Unfortunately, effective therapies for the management of enteropathy and restoring intestinal health are still not available. An accumulating body of preclinical studies has demonstrated that oral administration of plasma- or serum-derived protein concentrates containing high levels of immunoglobulins can improve weight, normalize gut barrier function, and reduce the severity of enteropathy in animal models. Recent studies in humans, using serum-derived bovine immunoglobulin/protein isolate, demonstrate that such protein preparations are safe and improve symptoms, nutritional status, and various biomarkers associated with enteropathy. Benefits have been shown in patients with HIV infection or diarrhea-predominant IBS. This review summarizes preclinical and clinical studies with plasma/serum protein concentrates and describes the effects on host nutrition, intestinal function, and markers of intestinal inflammation. It supports the concept that immunoglobulin-containing protein preparations may offer a new strategy for restoring functional homeostasis in the intestinal tract of patients with enteropathy.

Gut barrier dysfunction and microbial translocation in cancer cachexia: a new therapeutic target

Purpose of Review

Cachexia is a complex metabolic syndrome characterized by skeletal muscle and adipose tissue loss and is frequently associated with emaciation, anorexia, systemic inflammation, and metabolic dysfunction. Lack of a clear understanding of the cause of cancer cachexia has impeded progress in identifying effective therapeutic agents. This review summarizes recent publications on the role of gut barrier function, intestinal microbiota, and inflammation in the etiology of cancer cachexia and new therapeutic interventions that may benefit treatment strategies.

Recent Findings

Significant advances have been made in understanding the composition and metabolic capabilities of the intestinal microbiota and its impact on gut barrier function with implications for certain inflammatory-based diseases. Recent studies reported associations between intestinal permeability and endotoxemia with development of cancer cachexia and other metabolic disorders. Improvements in intestinal function and weight gain along with decreased inflammation have been reported for potential therapeutic agents such as eicosapentaenoic acid, immunoglobulin isolates, and probiotics.

Summary

Continued progress in the scientific understanding of the complex interplay between the intestinal microbiota, gut barrier function, and host inflammatory responses will uncover new therapeutic targets to help avoid the serious metabolic alterations associated with cachexia.

Gut Microbiota in HIV Infection: Implication for Disease Progression and Management

Survival rates among HIV patients have significantly improved since the introduction of antiretroviral therapy (ART) in HIV management. However, persistent disease progression and clinical complications in virally suppressed individuals point to additional contributing factors other than HIV replication; microbial translocation is one such factor. The role of underlying commensal microbes and microbial products that traverse the intestinal lumen into systemic circulation in the absence of overt bacteraemia is under current investigation. This review focuses on current knowledge of the complex microbial communities and microbial markers involved in the disruption of mucosal immune T-cells in the promotion of inflammatory processes in HIV infections. Unanswered questions and aims for future studies are addressed. We provide perspective for discussing potential future therapeutic strategies focused on modulating the gut microbiota to abate HIV disease progression.

Microbial translocation and cardiometabolic risk factors in HIV infection

The widespread access to antiretroviral treatment during the past decades has transformed HIV infection from a lethal disease to a chronic condition, in which the relative burden of non-AIDS-related chronic disorders such as cardiovascular disease, malignancy, renal, liver, and bone disease has increased. The adjusted relative risk for myocardial infarction is reported to be around 2-fold compared to that of the general population, which over time is likely to translate into increased absolute risk in an aging population. Thus, delineating potentially HIV-specific pathogenetic mechanisms is crucial in order to tailor novel strategies for prophylaxis and treatment. This review will focus on advances in the field that possibly link HIV-induced alterations of the gut mucosa and consequent microbial translocation to cardiometabolic risk factors in HIV infection. Recent work suggests that markers of microbial translocation are closely associated with several cardiovascular risk factors such as dyslipidemia, insulin resistance, hypertension, coagulation abnormalities, endothelial dysfunction, and carotid atherosclerosis. Future studies should investigate whether associations between microbial translocation and cardiovascular risk factors will translate into increased risk of acute events, and whether strategies to target gut microbiota and microbial translocation might reduce such a risk.

Serum-derived bovine immunoglobulin/protein isolate: postulated mechanism of action for management of enteropathy

The health and performance of the gastrointestinal tract is influenced by the interaction of a variety of factors, including diet, nutritional status, genetics, environment, stress, the intestinal microbiota, immune status, and gut barrier. Disruptions in one or more of these factors can lead to enteropathy or intestinal disorders that are known to occur in concert with certain disease states or conditions such as irritable bowel syndrome or human immunodeficiency virus (HIV) infection. Nutritional support in the form of a medical food along with current therapies could help manage the adverse effects of enteropathy, which include effects on nutrient digestion, absorption, and metabolism, as well as utilization of nutrients from foodstuffs. Numerous studies have demonstrated that oral administration of plasma- or serum-derived protein concentrates containing high levels of immunoglobulins can improve weight management, normalize gut barrier function, and reduce the severity of enteropathy in animals. Recent trials in humans provide preliminary evidence that a serum-derived bovine immunoglobulin/protein isolate is safe and improves symptoms, nutritional status, and various biomarkers associated with enteropathy in patients with HIV infection or diarrhea-predominant irritable bowel syndrome. This review summarizes data from preclinical and clinical studies with immunoglobulin-containing plasma/serum protein concentrates, with a focus on the postulated mode of action of serum-derived bovine immunoglobulin/protein isolate for patients with enteropathy.

Evaluation of serum-derived bovine immunoglobulin protein isolate in subjects with diarrhea-predominant irritable bowel syndrome

BACKGROUND

There is increased interest in combining nutritional modalities with pharmacological therapies for managing patients with diarrhea-predominant IBS (IBS-D).

AIM

A randomized, double-blind, placebo-controlled study to evaluate the impact of oral serum-derived bovine immunoglobulin/protein isolate (SBI) on gastrointestinal symptom scores and quality of life (QoL) in subjects with IBS-D.

METHODS

Study subjects previously diagnosed with IBS-D according to ROME II criteria were recruited from London, Ontario, Canada and assigned to receive 5 g/day SBI, 10 g/day SBI, or placebo for 6 weeks. Daily symptom frequency and severity scores and a modified IBS-36 questionnaire assessed the impact of nutritional intervention. Laboratory assessments were performed at screening and end of treatment (EOT) to evaluate safety. Within-group comparisons of changes in number of days per week with symptoms and symptom severity were conducted on the per-protocol population of subjects using a t-test.

RESULTS

Subjects who received SBI at 10 g/day (N = 15) had statistically significant within-group reductions in abdominal pain (p < 0.01), loose stools (p < 0.01), bloating (p < 0.05), flatulence (p < 0.01), urgency (p < 0.05) and any symptom (p < 0.01) at EOT vs. baseline. Subjects receiving 5 g/day of SBI (N = 15) realized statistically significant within-group reductions in days with flatulence (p < 0.035), incomplete evacuation (p < 0.05), and any symptom (p < 0.01). There were no significant changes in QoL scores or in hematology or clinical chemistry among treatment groups.

CONCLUSIONS

This pilot study showed that nutritional therapy with either 10 g/day or 5 g/day of SBI in 30 patients was well tolerated and resulted in statistically significant within group improvements in both symptom days and in daily symptom scores in subjects with IBS-D. Additional studies are underway with larger numbers of subjects to validate these findings.