Worming Their Way into the Picture: Microbiota Help Helminths Modulate Host Immunity.

Parasitic helminths are potent regulators of host immunity, including inhibition of allergic inflammation. In this issue of Immunity, Zaiss et al. (2015) reveal that microbiota compositional shifts during helminth infection contribute to the multifaceted ways that helminths modulate host immunity.

The benefits and acceptability of virtual reality interventions for women with metastatic breast cancer in their homes; a pilot randomised trial.

BACKGROUND: Women with metastatic breast cancer (MBC) report debilitating physical and psychological symptoms, including fatigue, anxiety, and pain, that greatly impact their quality of life. Immersive virtual reality (VR) has been proposed as an adjunctive pain therapy for patients with cancer, and evidence suggests it may also decrease symptoms of anxiety and depression. The purpose of this pilot study was to assess whether VR should be pursued as a feasible and acceptable adjunctive therapy to alleviate physical and psychological symptoms in women with MBC. METHODS: We conducted a pilot study testing the acceptability and efficacy of VR interventions with MBC patients to improve quality of life and to produce enduring decreases in fatigue, pain, depression, anxiety, and stress. Participants completed two different week-long VR experiences, reporting the prevalence of symptoms immediately before and after each study week, and 48 h later. Linear mixed models including fixed effects (VR intervention, counterbalancing order, and study week) and random effects (participant) were used to assess the effect of immersive VR on all outcome measures. RESULTS: Thirty-eight women with MBC completed the VR interventions and were included in analyses. Significant improvements post-intervention and/or 48 h later were demonstrated for quality of life, fatigue, pain, depression, anxiety, and stress. Across the entire study period, these differences met the criteria of a clinically important difference for quality of life, fatigue, depression, and stress. Participants reported feelings of relaxation and enjoyment and were highly likely to use the interventions gain. CONCLUSIONS: Our results demonstrate that VR experiences offer enduring benefits to the physical and psychological well-being of women with MBC. VR interventions are a feasible and acceptable intervention that can be conducted in a patient's own home. Such interventions are worthy of future investigation as a novel approach to improving quality of life in a patient population that have often been overlooked. TRIAL REGISTRATION: Prospectively registered on 25th October 2019 with Australian New Zealand Clinical Trials Registry (ref: ACTRN12619001480178 ).

Will I have sex to please you? Evaluating whether mindfulness buffers links between attachment and sexual motivations in daily life.

Insecurely attached individuals are more likely to report more maladaptive sexual motivations that predict worse personal and interpersonal outcomes. Given that mindfulness has been linked with improved relationship and sexual experiences, and that these effects may be moderated by attachment, the current study examined the possible buffering role of trait mindfulness on the links between attachment insecurity and daily sexual motives. Participants from New Zealand (N = 70) took part in a daily diary study that overcame limitations associated with previous cross-sectional research in the area (e.g., recall and aggregation biases). Online measures of trait mindfulness and attachment were completed, before participants reported their sexual motivations on each day they had sex for the next 14 days. Results provided some evidence that trait mindfulness has a therapeutic effect among more anxiously attached persons insofar as it reduced the degree to which attachment concerns manifested in maladaptive daily sexual motivations. In contrast, trait mindfulness did not buffer (and in some cases intensified) the links between attachment avoidance and maladaptive sexual motives. No significant interactions were detected between attachment insecurity and mindfulness in the prediction of adaptive daily sexual motivations. These findings suggest that mindfulness may differentially affect the manifestations of anxious and avoidant attachment. Practical and theoretical implications of the findings are discussed.

The perceptions of cancer health-care practitioners in New Zealand and the USA toward psychedelic-assisted therapy with cancer patients: A cross-sectional survey.

OBJECTIVES: A resurgence of research investigating the administration of psychedelic compounds alongside psychotherapy suggests that this treatment is a promising intervention for anxiety, depression, and existential distress in people with cancer. However, psychedelic treatment that induces a mind-altering experience potentially poses barriers to vulnerable cancer patients, and health-care practitioners may have concerns about referring their patients to trials investigating this approach. The aim of the current study was to investigate the perceptions of cancer health-care practitioners based in New Zealand and the USA related to psychedelic-assisted therapy. METHODS: This study utilized a cross-sectional survey of cancer health-care practitioners in New Zealand and the USA via convenience sampling to identify their perceptions about the concept of conducting psychedelic-assisted therapy with cancer patients. RESULTS: Participants perceived that (1) psychedelic-assisted therapy has the potential to provide benefit for cancer patients, (2) research in this area across a variety of domains is important, (3) work should consider spiritual and indigenous perspectives of health, and (4) there was willingness to refer patients to trials in this area, especially patients with advanced disease who were no longer going through curative treatment. Participants in the USA had greater awareness of psychedelics than the New Zealand sample; however, New Zealand participants more strongly believed that spiritual/indigenous factors should be considered in psychedelic-assisted therapy. SIGNIFICANCE OF RESULTS: Cancer health-care practitioners in our sample considered research investigating the potential for psychedelic-assisted therapies to be important and may be more open to studies that start in palliative and end-of-life contexts.

Small Intestinal Levels of the Branched Short-Chain Fatty Acid Isovalerate Are Elevated during Infection with Heligmosomoides polygyrus and Can Promote Helminth Fecundity.

Heligmosomoides polygyrus is a helminth which naturally infects mice and is widely used as a laboratory model of chronic small intestinal helminth infection. While it is known that infection with H. polygyrus alters the composition of the host's bacterial microbiota, the functional implications of this alteration are unclear. We investigated the impact of H. polygyrus infection on short-chain fatty acid (SCFA) levels in the mouse intestine and sera. We found that helminth infection resulted in significantly upregulated levels of the branched SCFA isovaleric acid, exclusively in the proximal small intestine, which is the site of H. polygyrus colonization. We next set out to test the hypothesis that elevating local levels of isovaleric acid was a strategy used by H. polygyrus to promote its own fitness within the mammalian host. To test this, we supplemented the drinking water of mice with isovalerate during H. polygyrus infection and examined whether this affected helminth fecundity or chronicity. We did not find that isovaleric acid supplementation affected helminth chronicity; however, we found that it did promote helminth fecundity, as measured by helminth egg output in the feces of mice. Through antibiotic treatment of helminth-infected mice, we found that the bacterial microbiota was required in order to support elevated levels of isovaleric acid in the proximal small intestine during helminth infection. Overall, our data reveal that during H. polygyrus infection there is a microbiota-dependent localized increase in the production of isovaleric acid in the proximal small intestine and that this supports helminth fecundity in the murine host.

The "Ick" Factor: An Unrecognized Affective Predictor of Physical Symptoms During Chemotherapy.

BACKGROUND: Patients undergoing chemotherapy experience a range of aversive symptoms. These symptoms vary across individuals and at least some of this variation can be predicted by psychological factors, such as distress. However, while psychological distress predicts some of the symptoms, it is limited in important ways. PURPOSE: To (a) assess the viability of disgust-a discrete emotion that specifically evolved for health-related reasons-as a predictor of chemotherapy-related symptoms (particularly, taste- and smell-related changes) and (b) compare the predictive utility of disgust sensitivity and propensity against the most commonly used affective predictor, that is, psychological distress. METHODS: Patients with cancer (N = 63) about to initiate chemotherapy were recruited in a prospective observational study. Psychosocial predictor variables were assessed at baseline, and outcomes (i.e., physical symptoms, body mass index [BMI], and food-based sensory-processing changes) were assessed at both baseline and 6 week follow-up. RESULTS: Psychological distress did not predict any of the outcomes. Both disgust sensitivity (ß = .53, p = .003) and propensity (ß = -.56, p = .002) predicted greater food-based sensory-processing changes, while disgust sensitivity marginally predicted greater chemotherapy-related physical symptoms (ß = .34, p = .060); neither of these two forms of disgust predicted BMI. CONCLUSIONS: The study provides first evidence showing (a) associations between trait disgust and food sensory-processing changes that arise during chemotherapy and (b) disgust as being a more useful predictor of food- and digestion-related symptoms than psychological distress. In doing so, it opens new doors for better care to be provided to patients undergoing chemotherapy.

"I Don't Identify with It": A Qualitative Analysis of People's Experiences of Living with Complex Regional Pain Styndrome.

OBJECTIVE: Complex regional pain syndrome (CRPS) is a painful limb condition known to cause significant disability and distress. However, little previous research has explored CRPS from a patient perspective. The present qualitative study aimed to describe the experiences of people living with CRPS. SUBJECTS: Forty-eight people with CRPS participated in this research. METHODS: Participants completed a face-to-face or telephone interview about their perceptions and experiences of CRPS and completed three drawings to illustrate their experiences. Data were analyzed through reflexive thematic analysis, and images in drawings were grouped and coded by theme. RESULTS: Three overarching themes encapsulated the data, including that 1) people experience CRPS as a source of severe symptoms and emotional difficulties, 2) CRPS undermines personal and social identity, and 3) this results in psychological responses that protect against the emotional and social impact of severe symptoms. Psychological responses include: a) searching for an explanation, b) "nothing is my fault," emphasizing a lack of personal responsibility and personal control, and c) detaching the limb from the self. CONCLUSIONS: CRPS is experienced as highly threatening to physical ability, psychological state, and identity. In response to these threats, people may develop their own explanations for CRPS and may mentally detach themselves from responsibility, control, and the painful limb itself. Future research could explore the impact of these factors on psychological well-being and CRPS symptoms and outcomes.

Mental health professionals' perceived barriers and enablers to shared decision-making in risk assessment and risk management: a qualitative systematic review.

BACKGROUND: Risk assessment and risk management are fundamental processes in the delivery of safe and effective mental health care, yet studies have shown that service users are often not directly involved or are unaware that an assessment has taken place. Shared decision-making in mental health systems is supported by research and advocated in policy. This systematic review (PROSPERO: CRD42016050457) aimed to explore the perceived barriers and enablers to implementing shared decision-making in risk assessment and risk management from mental health professionals' perspectives. METHODS: PRISMA guidelines were followed in the conduct and reporting of this review. Medline, CINAHL, EMBASE, PsycINFO, AMED and Internurse were systematically searched from inception to December 2019. Data were mapped directly into the Theoretical Domains Framework (TDF), a psychological framework that includes 14 domains relevant to behaviour change. Thematic synthesis was used to identify potential barriers and enablers within each domain. Data were then matched to the three components of the COM-B model: Capability, Opportunity, and Motivation. RESULTS: Twenty studies met the eligibility criteria. The findings of this review indicate that shared decision-making is not a concept commonly used in mental health services when exploring processes of risk assessment and risk management. The key barriers identified were 'power and best interest' (social influences) and 'my professional role and responsibility' (social/professional role and identity). Key enablers were 'therapeutic relationship' (social influences) and 'value collaboration' (reinforcement). The salient barriers, enablers and linked TDF domains matched COM-B components 'opportunity' and 'motivation'. CONCLUSION: The review highlights the need for further empirical research to better understand current practice and mental health professionals' experiences and attitudes towards shared decision-making in risk assessment and risk management.

Stigma in the face of cancer disfigurement: A systematic review and research agenda.

INTRODUCTION: An emerging body of work has reported on the psychological impact of disfigurement on cancer patients; however, the extent of research focusing on stigmatisation in this context is unclear. This review aimed to evaluate how stigma associated with disfigurement impacts on cancer patients. METHODS: A systematic review of literature was conducted using SCOPUS, Web of Science, MEDLINE and PubMed databases. Articles were included if they described a qualitative or quantitative study that investigated the impact of stigma and disfigurement on individuals with cancer and/or their families. Included studies were appraised for methodology and narratively synthesised. RESULTS: Of the 16 studies which met the inclusion criteria, ten were qualitative and six were quantitative. Publication dates ranged from 1994 to 2020. Results highlighted the varying impact of felt and enacted stigma in people with cancer disfigurement. While individuals cope with stigma in different ways and outcomes can sometimes be positive, most articles documented a negative impact to well-being including emotions such as disgust and shame. CONCLUSION: This review identified negative and (sometimes) positive consequences of disfigurement and stigma on cancer patients; however, the main finding is that relevant research is in its infancy. Several areas of future research are warranted.

When mental illness and cancer collide: An investigation of the predictors of outcomes for cancer patients with a history of mental health problems.

OBJECTIVE: People with a serious mental health condition are no more likely to receive a diagnosis of cancer than the general population but fare more poorly in terms of outcomes. The current study investigated whether a background of mental health problems (measured by contact with mental health services and psychotropic medication) predicted treatment outcomes over and above demographic and medical confounds for cancer patients at Counties Manukau Health. METHODS: The sample consisted of 1652 patients diagnosed with cancer in the period 1 January 2016 to 31 December 2016. The sample was split into three groups: non-mental health, moderate mental health, and serious mental health. RESULTS: Patients in the serious and moderate mental health groups were more likely to have physical comorbidities. Those in the serious mental health group were also marginally more likely to have advanced cancer at diagnosis. There were no differences between groups in terms of treatment delays, but patients in the serious mental health group were more likely to be hospitalised and die in the 12 months following diagnosis. Whilst differences in mortality may be explained by greater clinical complexity (being older, having other physical comorbidities) and later stage at presentation, mental health history was independently associated with hospitalisations. CONCLUSIONS: Cancer patients with a history of more serious mental health issues fare more poorly than those with moderate mental health issues or no such history. The clinical complexity of working with these patients, indexed by mental and physical comorbidities, may be a factor contributing to this disparity.

Functional specialization of intestinal dendritic cell subsets during Th2 helminth infection in mice.

Dendritic cells (DCs) are essential in dictating the nature and effectiveness of immune responses. In the intestine DCs can be separated into discrete subsets, defined by expression of CD11b and CD103, each with different developmental requirements and distinct functional potential. Recent evidence has shown that different intestinal DC subsets are involved in the induction of T helper (Th)17 and regulatory T cell responses, but the cells that initiate Th2 immune responses are still incompletely understood. We show that in the Th2 response to an intestinal helminth in mice, only CD11b+ and not CD11b- DCs accumulate in the local lymph node, upregulate PDL2 and express markers of alternative activation. An enteric Th1 response instead activated both CD11b+ and CD11b- DCs without eliciting alternative activation in either population. Functionally, only CD11b+ DCs activated during helminth infection supported Th2 differentiation in naive CD4+ T cells. Together our data demonstrate that the ability to prime Th2 cells during intestinal helminth infection, is a selective and inducible characteristic of CD11b+ DCs.

Parasite stress and pathogen avoidance relate to distinct dimensions of political ideology across 30 nations.

People who are more avoidant of pathogens are more politically conservative, as are nations with greater parasite stress. In the current research, we test two prominent hypotheses that have been proposed as explanations for these relationships. The first, which is an intragroup account, holds that these relationships between pathogens and politics are based on motivations to adhere to local norms, which are sometimes shaped by cultural evolution to have pathogen-neutralizing properties. The second, which is an intergroup account, holds that these same relationships are based on motivations to avoid contact with outgroups, who might pose greater infectious disease threats than ingroup members. Results from a study surveying 11,501 participants across 30 nations are more consistent with the intragroup account than with the intergroup account. National parasite stress relates to traditionalism (an aspect of conservatism especially related to adherence to group norms) but not to social dominance orientation (SDO; an aspect of conservatism especially related to endorsements of intergroup barriers and negativity toward ethnic and racial outgroups). Further, individual differences in pathogen-avoidance motives (i.e., disgust sensitivity) relate more strongly to traditionalism than to SDO within the 30 nations.

Bearing witness and being bounded: The experiences of nurses in adult critical care in relation to the survivorship needs of patients and families.

AIM: To discern and understand the responses of nurses to the survivorship needs of patients and family members in adult critical care units. BACKGROUND: The critical care environment is a demanding place of work which may limit nurses to immediacy of care, such as the proximity to death and the pressure of work. DESIGN: A constructivist grounded theory approach with constant comparative analysis. METHODS: As part of a wider study and following ethical approval, eleven critical care nurses working within a general adult critical care unit were interviewed with respect to their experiences in meeting the psychosocial needs of patients and family members. Through the process of constant comparative analysis, an overarching selective code was constructed. EQUATOR guidelines for qualitative research (COREQ) were applied. RESULTS: The data illuminated a path of developing expertise permitting integration of physical, psychological and family care with technology and humanity. Gaining such proficiency is demanding, and the data presented reveal the challenges that nurses experience along the way. CONCLUSION: The study confirms that working within a critical care environment is an emotionally charged challenge and may incur an emotional cost. Nurses can find themselves bounded by the walls of the critical care unit and experience personal and professional conflicts in their role. Nurses bear witness to the early stages of the survivorship trajectory but are limited in their support of ongoing needs. RELEVANCE TO CLINICAL PRACTICE: Critical care nurses can experience personal and professional conflicts when caring for both patients and families. This can lead to moral distress and may contribute to compassion fatigue. Critical care nurses appear bounded to the delivery of physiological and technical care, in the moment, as demanded by the patient's acuity. Consequentially, this limits nurses' ability to support the onward survivorship trajectory. Increased pressure and demands on critical care beds have contributed further to occupational stress in this care setting.

Constructing a grounded theory of critical illness survivorship: The dualistic worlds of survivors and family members.

AIM OF THE STUDY: To understand the critical illness trajectory from patient and relative perspectives. BACKGROUND: In the context of increasing survivorship from critical illness, it is important to enhance our understanding of the subjective experience of survivors and their families. The need to consider the legacy of critical care beyond physiological survival is imperative. METHODS: Using a constructivist grounded theory methodology, in-depth interviews were undertaken with survivors of critical illness (n = 16) and family members (n = 15). Constant comparative analysis and data collection occurring concurrently with theoretical sampling commencing from the outset. EQUATOR guidelines for qualitative research (COREQ) applied. FINDINGS: Survivors of critical illness invariably experienced vivid, hallucinatory experiences which placed them in a different world or liminal space. The core difficulty can be summarised as follows: Survivors have little recall of the factual events of their critical illness but relatives have lived the whole event in a very real and ingraining manner. This can result in family members and survivors experiencing different versions of the critical illness episode. CONCLUSION: Survivors of critical illness, together with family members, experience challenges when endeavouring to readjust to life post critical care. This study has identified a middle range theory of dualistic worlds between and within the survivor and family member experiences. Exploring the dynamic interplay between intrapersonal, interpersonal and societal factors has provided theoretical insights with practice implications in relation to surviving critical illness. RELEVANCE TO CLINICAL PRACTICE: The findings from this study highlight the need for a rehabilitation infrastructure following critical illness to support the existing UK national guidance, ensuring the individual and holistic needs of survivors and their families are met. Conversations with survivors and their families around critical illness survivorship are frequently absent and needed early in the recovery period.

The Nurses That Roared: Nurses From History Who Found Their Voices and Challenged the Status Quo.

In this article, we explore how nurses from history challenged norms of nursing and society, and consider how they can influence and inspire nurses today. We discuss the role of nurses in the fight for women's suffrage, campaigning for the vote, and caring for women who suffered in their fight to achieve it, and present examples of outstanding bravery in the past and present day. The article contains examples of the bravery of some relatively unknown nurses in wartime, who also fought for equality and inclusion, and nurses who challenged the care of marginalized groups, campaigning for improved treatment, sometimes at great personal cost. Finally, we consider the courage of present-day nurses. Drawing on the global campaign of "Nursing Now," we suggest that learning from these exceptional nurses and acknowledging and highlighting their contribution can inspire us to strengthen and promote nursing and to empower women globally.

Emotional predictors of bowel screening: the avoidance-promoting role of fear, embarrassment, and disgust.

BACKGROUND: Despite considerable efforts to address practical barriers, colorectal cancer screening numbers are often low. People do not always act rationally, and investigating emotions may offer insight into the avoidance of screening. The current work assessed whether fear, embarrassment, and disgust predicted colorectal cancer screening avoidance. METHODS: A community sample (N = 306) aged 45+ completed a questionnaire assessing colorectal cancer screening history and the extent that perceptions of cancer risk, colorectal cancer knowledge, doctor discussions, and a specifically developed scale, the Emotional Barriers to Bowel Screening (EBBS), were associated with previous screening behaviours and anticipated bowel health decision-making. RESULTS: Step-wise logistic regression models revealed that a decision to delay seeking healthcare in the hypothetical presence of bowel symptoms was less likely in people who had discussed risk with their doctor, whereas greater colorectal cancer knowledge and greater fear of a negative outcome predicted greater likelihood of delay. Having previously provided a faecal sample was predicted by discussions about risk with a doctor, older age, and greater embarrassment, whereas perceptions of lower risk predicted a lower likelihood. Likewise, greater insertion disgust predicted a lower likelihood of having had an invasive bowel screening test in the previous 5 years. CONCLUSIONS: Alongside medical and demographic factors, fear, embarrassment and disgust are worthy of consideration in colorectal cancer screening. Understanding how specific emotions impact screening decisions and behaviour is an important direction for future work and has potential to inform screening development and communications in bowel health.

Direct measurement of oxidative and nitrosative stress dynamics in Salmonella inside macrophages.

Many significant bacterial pathogens have evolved virulence mechanisms to evade degradation and exposure to reactive oxygen (ROS) and reactive nitrogen species (RNS), allowing them to survive and replicate inside their hosts. Due to the highly reactive and short-lived nature of ROS and RNS, combined with limitations of conventional detection agents, the mechanisms underlying these evasion strategies remain poorly understood. In this study, we describe a system that uses redox-sensitive GFP to nondisruptively measure real-time fluctuations in the intrabacterial redox environment. Using this system coupled with high-throughput microscopy, we report the intrabacterial redox dynamics of Salmonella enterica Typhimurium (S. Typhimurium) residing inside macrophages. We found that the bacterial SPI-2 type III secretion system is required for ROS evasion strategies and this evasion relies on an intact Salmonella-containing vacuole (SCV) within which the bacteria reside during infection. Additionally, we found that cytosolic bacteria that escape the SCV experience increased redox stress in human and murine macrophages. These results highlight the existence of specialized evasion strategies used by intracellular pathogens that either reside inside a vacuole or "escape" into the cytosol. Taken together, the use of redox-sensitive GFP inside Salmonella significantly advances our understanding of ROS and RNS evasion strategies during infection. This technology can also be applied to measuring bacterial oxidative and nitrosative stress dynamics under different conditions in a wide variety of bacteria.

Enteric Helminths Promote Salmonella Coinfection by Altering the Intestinal Metabolome.

Intestinal helminth infections occur predominantly in regions where exposure to enteric bacterial pathogens is also common. Helminth infections inhibit host immunity against microbial pathogens, which has largely been attributed to the induction of regulatory or type 2 (Th2) immune responses. Here we demonstrate an additional 3-way interaction in which helminth infection alters the metabolic environment of the host intestine to enhance bacterial pathogenicity. We show that an ongoing helminth infection increased colonization by Salmonella independently of T regulatory or Th2 cells. Instead, helminth infection altered the metabolic profile of the intestine, which directly enhanced bacterial expression of Salmonella pathogenicity island 1 (SPI-1) genes and increased intracellular invasion. These data reveal a novel mechanism by which a helminth-modified metabolome promotes susceptibility to bacterial coinfection.

Concerted activity of IgG1 antibodies and IL-4/IL-25-dependent effector cells trap helminth larvae in the tissues following vaccination with defined secreted antigens, providing sterile immunity to challenge infection.

Over 25% of the world's population are infected with helminth parasites, the majority of which colonise the gastrointestinal tract. However, no vaccine is yet available for human use, and mechanisms of protective immunity remain unclear. In the mouse model of Heligmosomoides polygyrus infection, vaccination with excretory-secretory (HES) antigens from adult parasites elicits sterilising immunity. Notably, three purified HES antigens (VAL-1, -2 and -3) are sufficient for effective vaccination. Protection is fully dependent upon specific IgG1 antibodies, but passive transfer confers only partial immunity to infection, indicating that cellular components are also required. Moreover, immune mice show greater cellular infiltration associated with trapping of larvae in the gut wall prior to their maturation. Intra-vital imaging of infected intestinal tissue revealed a four-fold increase in extravasation by LysM+GFP+ myeloid cells in vaccinated mice, and the massing of these cells around immature larvae. Mice deficient in FcRγ chain or C3 complement component remain fully immune, suggesting that in the presence of antibodies that directly neutralise parasite molecules, the myeloid compartment may attack larvae more quickly and effectively. Immunity to challenge infection was compromised in IL-4Rα- and IL-25-deficient mice, despite levels of specific antibody comparable to immune wild-type controls, while deficiencies in basophils, eosinophils or mast cells or CCR2-dependent inflammatory monocytes did not diminish immunity. Finally, we identify a suite of previously uncharacterised heat-labile vaccine antigens with homologs in human and veterinary parasites that together promote full immunity. Taken together, these data indicate that vaccine-induced immunity to intestinal helminths involves IgG1 antibodies directed against secreted proteins acting in concert with IL-25-dependent Type 2 myeloid effector populations.

Cohabitation in the Intestine: Interactions among Helminth Parasites, Bacterial Microbiota, and Host Immunity.

Both intestinal helminth parasites and certain bacterial microbiota species have been credited with strong immunomodulatory effects. Recent studies reported that the presence of helminth infection alters the composition of the bacterial intestinal microbiota and, conversely, that the presence and composition of the bacterial microbiota affect helminth colonization and persistence within mammalian hosts. This article reviews recent findings on these reciprocal relationships, in both human populations and mouse models, at the level of potential mechanistic pathways and the implications these bear for immunomodulatory effects on allergic and autoimmune disorders. Understanding the multidirectional complex interactions among intestinal microbes, helminth parasites, and the host immune system allows for a more holistic approach when using probiotics, prebiotics, synbiotics, antibiotics, and anthelmintics, as well as when designing treatments for autoimmune and allergic conditions.