Participants in the Trans-Antarctic Winter Traverse Expedition Showed Increased Bacterial Load and Diversity in Saliva but Maintained Individual Differences within Stool Microbiota and Across Metabolite Fingerprints.

Understanding the impact of long-term physiological and environmental stress on the human microbiota and metabolome may be important for the success of space flight. This work is logistically difficult and has a limited number of available participants. Terrestrial analogies present important opportunities to understand changes in the microbiota and metabolome and how this may impact participant health and fitness. Here, we present work from one such analogy: the Transarctic Winter Traverse expedition, which we believe is the first assessment of the microbiota and metabolome from different bodily locations during prolonged environmental and physiological stress. Bacterial load and diversity were significantly higher during the expedition when compared with baseline levels (p < 0.001) in saliva but not stool, and only a single operational taxonomic unit assigned to the Ruminococcaceae family shows significantly altered levels in stool (p < 0.001). Metabolite fingerprints show the maintenance of individual differences across saliva, stool, and plasma samples when analysed using flow infusion electrospray mass spectrometry and Fourier transform infrared spectroscopy. Significant activity-associated changes in terms of both bacterial diversity and load are seen in saliva but not in stool, and participant differences in metabolite fingerprints persist across all three sample types.

Optimising an intervention to support home-living older adults at risk of malnutrition: a qualitative study.

BACKGROUND: In the UK, about 14% of community-dwelling adults aged 65 and over are estimated to be at risk of malnutrition. Screening older adults in primary care and treating those at risk may help to reduce malnutrition risk, reduce the resulting need for healthcare use and improve quality of life. Interventions are needed to raise older adults' risk awareness, offer relevant and meaningful strategies to address risk and support general practices to deliver treatment and support. METHODS: Using the Person-based Approach and input from Patient and Public Involvement representatives, we developed the 'Eat well, feel well, stay well' intervention. The intervention was optimised using qualitative data from think aloud and semi-structured process evaluation interviews with 23 and 18 older adults respectively. Positive and negative comments were extracted to inform rapid iterative modifications to support engagement with the intervention. Data were then analysed thematically and final adjustments made, to optimise the meaningfulness of the intervention for the target population. RESULTS: Participants' comments were generally positive. This paper focuses predominantly on participants' negative reactions, to illustrate the changes needed to ensure that intervention materials were optimally relevant and meaningful to older adults. Key factors that undermined engagement included: resistance to the recommended nutritional intake among those with reduced appetite or eating difficulties, particularly frequent eating and high energy options; reluctance to gain weight; and a perception that advice did not align with participants' specific personal preferences and eating difficulties. We addressed these issues by adjusting the communication of eating goals to be more closely aligned with older adults' beliefs about good nutrition, and acceptable and feasible eating patterns. We also adjusted the suggested tips and strategies to fit better with older adults' everyday activities, values and beliefs. CONCLUSIONS: Using iterative qualitative methods facilitated the identification of key behavioural and contextual elements that supported engagement, and issues that undermined older adults' engagement with intervention content. This informed crucial revisions to the intervention content that enabled us to maximise the meaningfulness, relevance and feasibility of the key messages and suggested strategies to address malnutrition risk, and therefore optimise engagement with the intervention and the behavioural advice it provided.

100 years since Scott reached the pole: a century of learning about the physiological demands of Antarctica.

The 1910-1913 Terra Nova Expedition to the Antarctic, led by Captain Robert Falcon Scott, was a venture of science and discovery. It is also a well-known story of heroism and tragedy since his quest to reach the South Pole and conduct research en route, while successful was also fateful. Although Scott and his four companions hauled their sledges to the Pole, they died on their return journey either directly or indirectly from the extreme physiological stresses they experienced. One hundred years on, our understanding of such stresses caused by Antarctic extremes and how the body reacts to severe exercise, malnutrition, hypothermia, high altitude, and sleep deprivation has greatly advanced. On the centenary of Scott's expedition to the bottom of the Earth, there is still controversy surrounding whether the deaths of those five men could have, or should have, been avoided. This paper reviews present-day knowledge related to the physiology of sustained man-hauling in Antarctica and contrasts this with the comparative ignorance about these issues around the turn of the 20th century. It closes by considering whether, with modern understanding about the effects of such a scenario on the human condition, Scott could have prepared and managed his team differently and so survived the epic 1,600-mile journey. The conclusion is that by carrying rations with a different composition of macromolecules, enabling greater calorific intake at similar overall weight, Scott might have secured the lives of some of the party, and it is also possible that enhanced levels of vitamin C in his rations, albeit difficult to achieve in 1911, could have significantly improved their survival chances. Nevertheless, even with today's knowledge, a repeat attempt at his expedition would by no means be bound to succeed.

Overfeeding and overhydration in elderly medical patients: lessons from the Liverpool Care Pathway.

This paper describes three elderly patients who were admitted to hospital with aspiration pneumonia. They were kept nil by mouth (NBM) for a number of days, while being given intravenous hydration initially and enteral feeding subsequently. During that time they deteriorated and appeared to be dying, so the Liverpool Care Pathway (LCP) for the dying was used to support their care. Artificial nutrition and hydration were stopped. They quickly improved and the LCP was discontinued. Two of the patients deteriorated again on reintroduction of enteral feeding and/or intravenous fluids, only to improve a second time following withdrawal of feeding and fluids. Vulnerable elderly patients should not be made NBM except as a last resort. Clinicians should be alert to the possibility of refeeding syndrome and overhydration as reversible causes of clinical deterioration, particularly in frail elderly patients. Use of the LCP in these patients provided a unique opportunity to witness the positive effects of withdrawal of excessive artificial nutrition and hydration.

Does hands-free drinking improve patient hydration?

Hospital patients are at risk of dehydration, especially if they cannot drink unaided due to physical or mental incapacity. Dehydration may lead to complications and result in costly interventions. A sports-style bottle has been developed into a hands-free drinking system by fitting a drinking tube into the screw top. We trialled the bottle on acute wards and in the community to test claims that it improves hydration and reduces infection risks and length of hospital stays. The Hydrant is useful and even transformative for some patients. However, it is less suitable for older people, especially those in rehabilitation programmes.

Improving outpatient services: the Southampton IBD virtual clinic.

The follow-up of inflammatory bowel disease (IBD) patients is challenging due to the relapsing remitting nature of the diseases, the wide spectrum of severity and complexity as well as the need for monitoring of long-term complications and drug treatments. Conventional outpatient follow-up lacks flexibility for patients and there are competing pressures for clinic time. Alternative follow-up pathways include telephone clinics, self-management programmes or discharging patients. The IBD virtual clinic (VC) is a further option. Patients with an established diagnosis for >2 years, who have been stable for >1 year, do not have primary sclerosing cholangitis and who give their consent, are entered into the VC system. Two months before their annual follow-up is due patients are sent blood test forms and a simple questionnaire with an information sheet. If they meet any of the criteria on the questionnaire, they are asked to contact the IBD specialist nursing team to discuss their situation. The blood test results and the patient's database entry are reviewed to ensure that they are not due surveillance investigations. The patients and their GPs then receive a letter informing them of their management plan. We currently follow-up 20% of the Southampton IBD cohort using the VC. The VC system is an innovative, efficient and patient-responsive method for following up mild to moderate IBD. It is well liked by patients but is dependent on a well-maintained database with good integration of IT systems and requires both clerical and IBD nurse specialist support.

Refeeding risks in patients requiring intravenous nutrition support: Results of a two-centre, prospective, double-blind, randomised controlled trial.

BACKGROUND/AIMS: Refeeding syndrome can result following excessive feeding of malnourished patients. The syndrome remains poorly defined but encompasses a range of adverse effects including electrolyte shifts, hyperglycaemia and other less well-defined phenomena. There are additional risks of underfeeding malnourished individuals. Studies of refeeding syndrome have generally focussed on critical care environments or patients with anorexia nervosa. Here we have conducted a two-centre, prospective, double-blind, randomised controlled trial amongst all patients referred to hospital nutrition support teams for intravenous nutrition support. We sought to determine whether electrolyte and other abnormalities suggestive of refeeding syndrome risk varied depending on initial rate of intravenous feeding. METHODS: Patients at moderate or high risk of refeeding syndrome, as defined by United Kingdom National Institute of Health and Care Excellence guidelines, were screened for inclusion. Patients were randomised to receive either high (30 kcal/kg/day, 0.25 gN/kg/day) or low (15 kcal/day, 0.125 gN/kg/day) rate feeding for the first 48 h prior to escalation to standard parenteral nutrition regimens. The primary outcome was rates of potential refeeding risks within the first 7 days as defined by electrolyte imbalance or hyperglycaemia requiring insulin. Secondary outcomes included effects on QTc interval, infections and length of hospital stay. Statistical analysis was performed with χ2 or Wilcoxon rank sum tests and all analysis was intention-to-treat. Problems with study recruitment led to premature termination of the trial. Registered on the EU Clinical Trials Register (EudraCT number 2007-005547-17). RESULTS: 534 patients were screened and 104 randomised to either high or low rate feeding based on risk of refeeding syndrome. Seven patients were withdrawn prior to collection of baseline demographics and were excluded from analysis. 48 patients were analysed for the primary outcome with potential refeeding risks identified in 46%. No differences in risks were seen between high and low rate feeding (p > 0.99) or high and moderate risk feeding (p = 0.68). There were no differences in QTc abnormalities, infection rates, or hospital length of stay between groups. CONCLUSIONS: In this randomised trial of rates of refeeding risk, in patients pre-stratified as being at high or moderate risk, we found no evidence of increased refeeding related disturbances in those commenced on high rate feeding compared to low rate. No differences were seen in secondary endpoints including cardiac rhythm analysis, infections or length of stay. Our study reflects real world experience of patients referred for nutrition support and highlights challenges encountered when conducting clinical nutrition research.

Blood Flow Restriction Training for the Rotator Cuff: A Randomized Controlled Trial.

CONTEXT: Blood flow restriction (BFR) training utilizes a tourniquet, applied to the proximal portion of one or more extremities, to occlude blood flow during exercise. Significant gains in strength and cross-sectional area can be achieved in muscles, both distal and proximal to BFR cuff application. PURPOSE: To compare strength gains of the rotator cuff and changes in tendon size in subjects who performed side-lying external-rotation exercise with or without BFR. METHODS: Forty-six subjects (mean age 25.0 [2.2] y) were randomized to either a BFR + exercise group or to the exercise-only group. Subjects performed 4 sets of the exercise (30/15/15/15 repetitions) at 30% 1-repetition maximum 2 days per week for 8 weeks. RESULTS: Subjects in both groups experienced strength gains in the supraspinatus and the external rotators (P = .000, P = .000). However, there was no difference in strength gains between groups for the supraspinatus (P = .750) or the external rotators (P = .708). Subjects in both groups experienced increases in supraspinatus tendon thickness (BFR P = .041, exercise only P = .011). However, there was no difference between groups (P = .610). CONCLUSIONS: Exercise with BFR applied to the proximal upper extremity did not augment rotator cuff strength gains or tendon thickness when compared with subjects who only exercised. This study did demonstrate that performing multiple sets of high repetitions at a low load led to significant increases in rotator cuff strength and tendon size in the dominant upper extremity.

Human physiological and metabolic responses to an attempted winter crossing of Antarctica: the effects of prolonged hypobaric hypoxia.

An insufficient supply of oxygen to the tissues (hypoxia), as is experienced upon high-altitude exposure, elicits physiological acclimatization mechanisms alongside metabolic remodeling. Details of the integrative adaptive processes in response to chronic hypobaric hypoxic exposure remain to be sufficiently investigated. In this small applied field study, subjects (n = 5, male, age 28-54 years) undertook a 40 week Antarctica expedition in the winter months, which included 24 weeks residing above 2500 m. Measurements taken pre- and postexpedition revealed alterations to glucose and fatty acid resonances within the serum metabolic profile, a 7.8 (±3.6)% increase in respiratory exchange ratio measured during incremental exercise (area under curve, P > 0.01, mean ± SD) and a 2.1(±0.8) % decrease in fat tissue (P < 0.05) postexpedition. This was accompanied by an 11.6 (±1.9) % increase (P > 0.001) in VO2 max corrected to % lean mass postexpedition. In addition, spine bone mineral density and lung function measures were identified as novel parameters of interest. This study provides, an in-depth characterization of the responses to chronic hypobaric hypoxic exposure in one of the most hostile environments on Earth.

Fish oil and antioxidants alter the composition and function of circulating mononuclear cells in Crohn disease.

BACKGROUND: Crohn disease (CD) is associated with osteoporosis and other extraintestinal manifestations that might be mediated by cytokines from circulating (peripheral blood) mononuclear cells (PBMCs). Fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduces disease activity in patients with CD with raised laboratory markers of inflammation and in healthy subjects alters PBMC function. OBJECTIVE: We investigated the effect of fish oil plus antioxidants on cytokine production by PBMCs from patients with CD with raised C-reactive protein concentrations (>/=6.9 mg/L) or erythrocyte sedimentation rates (>/=18 mm/h). DESIGN: A randomized placebo-controlled trial of fish oil (2.7 g EPA and DHA/d; n = 31) or placebo (olive oil; n = 31) for 24 wk was conducted in patients with CD. The fish-oil group additionally received an antioxidant preparation (vitamins A, C, and E and selenium). Exclusion criteria included corticosteroid use. Fatty acid composition was measured by gas chromatography. Production of tumor necrosis factor alpha, interferon gamma (IFN-gamma), and prostaglandin E(2) (PGE(2)) was measured by enzyme-linked immunosorbent assays after stimulation with mitogen and endotoxin (lipopolysaccharide). RESULTS: Fish-oil plus antioxidant dietary supplementation was associated with higher EPA and DHA incorporation into PBMCs (P < 0.001) and lower arachidonic acid (P = 0.006) and lower production of IFN-gamma by mitogen-stimulated PBMCs (P = 0.012) and of PGE(2) by lipopolysaccharide-stimulated PBMCs (P = 0.047). CONCLUSION: Dietary supplementation with fish oil plus antioxidants is associated with modified PBMC composition and lower production of PGE(2) and IFN-gamma by circulating monocytes or macrophages. The response of extraintestinal manifestations of CD should be investigated in a randomized controlled trial.

Prostaglandin E2 production and T cell function after fish-oil supplementation: response to antioxidant cosupplementation.

BACKGROUND: Prostaglandin E(2) (PGE(2)) inhibits lymphocyte proliferation and the production of interferon-gamma (IFN-gamma) by peripheral blood mononuclear cells, but the effect of PGE(2) on interleukin 4 (IL-4) production is unclear. Fish oil, which contains eicosapentaenoic and docosahexaenoic acids, inhibits production of PGE(2). The effects of fish oil on lymphocyte proliferation and production of IFN-gamma and IL-4 are unclear and may be influenced by the availability of antioxidants. OBJECTIVE: We investigated the effect of dietary fish oil with and without antioxidant cosupplementation on lymphocyte proliferation and the production of PGE(2), IFN-gamma, and IL-4 by peripheral blood mononuclear cells. DESIGN: Sixteen healthy men received dietary fish-oil supplements providing 0.3, 1, and 2 g eicosapentaenoic acid plus docosahexaenoic acid/d for 4 consecutive weeks each (total of 12 wk). All subjects were randomly assigned to daily cosupplementation with either antioxidants (200 microg Se, 3 mg Mn, 30 mg RRR-alpha-tocopheryl succinate, 90 mg ascorbic acid, 450 micro g vitamin A) or placebo. RESULTS: Fish-oil supplementation decreased PGE(2) production and increased IFN-gamma production and lymphocyte proliferation from baseline values. Cosupplementation with antioxidants did not affect cytokine production or lymphocyte proliferation. CONCLUSION: Dietary fish oil modulates production of IFN-gamma and lymphocyte proliferation in a manner consistent with decreased production of PGE(2), but this effect is not modified by antioxidant cosupplementation.

Peripheral blood mononuclear cell fatty acid composition and inflammatory mediator production in adult Crohn's disease.

BACKGROUND & AIMS: Crohn's disease (CD) is associated with nutritional deficiencies, altered plasma concentrations of polyunsaturated fatty acids (PUFA) and an anti-inflammatory response to fish oil that contains n-3 PUFA. This suggests that, in CD, immune cells may have altered n-3 PUFA composition with functional consequences. The aim of this study is to investigate n-3 and n-6 PUFA composition and synthetic function of peripheral blood mononuclear cells (PBMC) in the basal state. METHODS: A case control study of 52 adult CD patients and healthy, age- and sex-matched controls. Composition of PBMC and plasma phospholipids were measured by gas chromatography and production of tumour necrosis factor-alpha, prostaglandin E2 (PGE2) and interferon-gamma (IFN-gamma) by PBMC were measured by ELISA. RESULTS: CD was associated with higher concentrations of eicosapentaenoic acid and other n-3 PUFA, and lower arachidonic acid (AA) (n-6 PUFA) in PBMC. This was not explained by differences in dietary fat intake. Lower rates of production of PGE2 and IFN-gamma by PBMC were noted in quiescent and active CD, respectively, compared to controls. CONCLUSIONS: CD is associated with a greater availability, and not a deficiency, of n-3 PUFA in PBMC, but lower concentrations of AA, and lower rates of production of PGE2 and IFN-gamma, compared to healthy controls.

Improving outpatient services: the Southampton IBD virtual clinic.

The follow-up of inflammatory bowel disease (IBD) patients is challenging due to the relapsing remitting nature of the diseases, the wide spectrum of severity and complexity as well as the need for monitoring of long-term complications and drug treatments. Conventional outpatient follow-up lacks flexibility for patients and there are competing pressures for clinic time. Alternative follow-up pathways include telephone clinics, self-management programmes or discharging patients. The IBD virtual clinic (VC) is a further option. Patients with an established diagnosis for >2 years, who have been stable for >1 year, do not have primary sclerosing cholangitis and who give their consent, are entered into the VC system. Two months before their annual follow-up is due patients are sent blood test forms and a simple questionnaire with an information sheet. If they meet any of the criteria on the questionnaire, they are asked to contact the IBD specialist nursing team to discuss their situation. The blood test results and the patient's database entry are reviewed to ensure that they are not due surveillance investigations. The patients and their GPs then receive a letter informing them of their management plan. We currently follow-up 20% of the Southampton IBD cohort using the VC. The VC system is an innovative, efficient and patient-responsive method for following up mild to moderate IBD. It is well liked by patients but is dependent on a well-maintained database with good integration of IT systems and requires both clerical and IBD nurse specialist support.

Could Scott have survived with today's physiological knowledge?

In 1911, members of a British expedition walked across the Antarctic to the South Pole, but in the punishingly hostile environment, retracing their steps back to the edge of the continent proved fatal. Over the last 100 years, knowledge about human physiology has greatly increased and, on the centenary of this most extreme of all journeys, this essay explores the true extent of the physiological stress experienced by the men involved and whether their fate was inevitable.

Malnutrition and nutrition support in patients with liver disease.

Liver disease, especially alcohol related, is increasingly common and is often accompanied by malnutrition as a result of reduced intake, absorption, processing and storage of nutrients. An increase or alteration in metabolic demands also occurs and some patients have high nutrient losses. Malnutrition in all forms of liver disease is associated with higher rates of mortality and morbidity but it is often under recognised and under treated despite the fact that appropriate treatment can improve outcomes. In this review, the causes, consequences and assessment of nutritional status in patients with liver disease are examined, and an approach to best treatment is proposed.

Protein and the critically ill; do we know what to give?

The National Institute for Health and Clinical Excellence (NICE) has recommended that nutrition support in seriously-ill or injured patients should start at 50% of the estimated target energy and protein needs. This recommendation has caused some concern, since taking the NICE approach leads to these sick individuals receiving an initial N provision of only 0.12 g N/kg per d, as opposed to levels of approximately 0.25 g N/kg per d that have been widely recommended by other expert groups. The basis of the recommendation for higher levels of N provision is that feeding at levels of >/=0.25 g N/kg per d reduces the inevitable net N loss of catabolism and hence minimises overall lean tissue wasting. However, although it has always been assumed that better N balance must equate with better outcome, there are teleological arguments that question the wisdom of providing more N to sicker patients and studies that imply that best N balance might not equate with best clinical progress. Furthermore, current evidence suggests that in most critical illness low initial intakes of both energy and N lead to improved survival. It therefore seems logical to aim, in the first instance, to feed the seriously ill at only modest levels. Further research is required to determine whether lower-energy higher-N feeding would prove better or worse than this approach in terms of clinical benefit rather than just better N retention. Investigations to explore the use of feeds that are specifically designed to match the amino acid needs of illness are also required.