Increased intestinal leakiness and associated systemic inflammation are potential contributors to osteoarthritis (OA) and postural imbalance in the geriatric population. To date, no successful treatment to correct postural imbalance in OA is known. We aimed to explore the effects of a multistrain probiotic upon postural imbalance in OA-affected patients. In this randomised, double-blind trial with a placebo group, 147 patients suffering from knee OA (age span = 64–75 years) were divided into placebo (n 75) and probiotics (n 72) study groups. Vivomix 112 billion, multistrain probiotic was given once a day for 12 weeks. The outcomes of study variables were determined first at baseline and later after 12 weeks of intervention. These were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), knee flexion range of motion (ROM), pain intensity by visual analogue scale, handgrip strength (HGS), gait speed and balance control assessed in standing, semi-tandem and tandem stances. We determined plasma zonulin to determine intestinal leak along with c-reactive protein and 8-isoprostanes levels. A total of 136 OA patients taking placebo (n 71) and probiotics (n 65) were analysed. The probiotics group exhibited a reduction in pain intensity, disease severity and WOMAC scores along with improvement in balance scores, HGS and walking speed (P < 0·05 for all), no change in ROM, resting pain and 8-isoprostanes levels. The correlation analysis revealed a robust association of balance scores with plasma markers of intestinal leakiness and inflammation in probiotics but not in the placebo group. Probiotics reduce postural imbalance in OA patients partly due to a reduction in intestinal leakiness.

I did not intend to revisit the discussion of the publication of Brandolini et al.1 on Ca urinary excretion attributed to the sulfate content of water but in their answers2 to my comments3, they said that ‘I accept their experimental results’ and that ‘I do not contest the difference in calciuria between milk and sulfate-rich water’. I never wrote that I agree with their results and even more with their conclusions but questioned how is it possible to evaluate a 20 mg difference in daily Ca urinary excretion from a study with subjects under uncontrolled dietary intakes, unbalanced experimental study design and without analytical results on acid–base balance and sulfate to support their acidogenic hypothesis of sulfate. I did not find any convincing explanations in their answers but I want to raise several points of disagreement, which are either repeated or new.

Most human intervention studies have examined the effects on a subset of risk factors, some of which may require long-term exposure. The plasma proteome may reflect the underlying changes in protein expression and activation, and this could be used to identify early risk markers. The aim of the present study was to evaluate the impact of regular fish intake on the plasma proteome. We recruited thirty healthy men aged 40 to 70 years, who were randomly allocated to a daily meal of chicken or trout raised on vegetable or marine feeds. Blood samples were collected before and after 8 weeks of intervention, and after the removal of the twelve most abundant proteins, plasma proteins were separated by two-dimensional gel electrophoresis. Protein spots < 66 kDa with a pI >4·3 visualised by silver staining were matched by two-dimensional imaging software. Within-subject changes in spots were compared between the treatment groups. Differentially affected spots were identified by matrix-assisted laser desorption ionisation-time of flight/time of flight MS and the human Swiss-Prot database. We found 23/681 abundant plasma protein spots, which were up- or down-regulated by the dietary treatment (P< 0·05, q< 0·30), and eighteen of these were identified. In each trout group, ten spots differed from those in subjects given the chicken meal, but only three of these were common, and only one spot differed between the two trout groups. In both groups, the affected plasma proteins were involved in biological processes such as regulation of vitamin A and haem transport, blood fibrinolysis and oxidative defence. Thus, regular fish intake affects the plasma proteome, and the changes may indicate novel mechanisms of effect.

1. The abomasal hydrolysis of lipids and the flow of endogenous (biliary) lipids was studied in two Friesian calves given four milk-substitute diets, by sampling the duodenal digesta. The diets were: reconstituted, mildly preheated, spray-dried skim-milk powder with (SKF) or without (SK) margarine fat or with 500 g/kg skim-milk powder in diet SKF replaced by soya-bean flour (ASKF) or fish-protein concentrate (BSKF) together with dried whey. The diets were given ad lib. twice daily from 13 to 37 d of age, each diet being given for six consecutive days. Collections of duodenal digesta from the re-entrant cannula situated caudal to the bile duct were made for 12 h after feeding the 6th and 12th meals for each diet. Samples from one collection only were subjected to detailed analysis of the lipid classes.

2. The inclusion of non-milk protein (ASKF and BSKF) not only increased the rate of passage of lipid through the abomasum but also the proportion of the lipid present as triglyceride particularly, in the first 2 h after feeding.

3. In a 12 h period, 2·3–6·3 g ‘polar’ lipids (mainly biliary phospholipids) were estimated to have been secreted. The rate of flow was high during the first hour after feeding and constant thereafter. The quantity of ‘polar’ lipid was not related to the type of milk fed or the duodenal flow of lipid.

4. When diet SK was fed, the small amounts of lipid present were extensively hydrolysed so that free fatty acids represented 700 g/kg lipid of dietary origin passing through the duodenum. When margarine fat was included in the diets (SKF, ASKF and BSKF), the free fatty acids represented only 210 g/kg lipid of dietary origin.

5. The quantities of lipid and nitrogen passing through the duodenum were poorly related to the quantities ingested at the beginning of the 12 h experimental period but were closely related to each other.

1. A method for producing a standard low-fluoride diet from a green alga and yeast is described. Chlorella pyrenoidosa was grown in a culture medium prepared with distilled water and analytical grade chemical salts. The spent culture medium from the alga culture was reclaimed and replenished with salts and sucrose for the production of yeast, Saccharomyces cerevisiae.

2. The single-cell organisms were separated by centrifugation from their culture media and the dried cells were blended with sucrose, maize oil, cellulose and a salt mix to produce diet pellets for rats and mice.

3. The diet was readily accepted as food by rats and mice and it was found to contain 100–300 μg fluoride/kg dry weight. Two generations of rats and four generations of mice were bred on this diet.

4. The use of hydroxyapatite to reduce the fluoride content of the chemicals used in the production of the alga and yeast biomass was investigated. Diet pellets prepared with this biomass contained 45–60 μg fluoride/kg dry weight.

1. The effect of vitamin B12 on growth was studied in young male and female rats fed on diets sufficient (+B12) or deficient (−B12) in vitamin B12 containing 30% of the dietary energy as fat, either maize oil (CO) or triundecanoin (TUD).

2. Vitamin B12 deficiency severely depressed growth. After 6 weeks the weight gain of CO(−B12) rats was only 72% of that of CO(+B12) rats and the gain of TUD(−B12) rats was only 47% of TUD(+B12) rats.

3. After fasting 24 or 96 h TUD-fed rats, both + B12 and −B12, had greater glycogen reserves and higher plasma glucose levels than CO-fed rats.

4. It is concluded that vitamin B12 is required for the metabolism and utilization of both an odd-carbon-number medium-chain fat, TUD, and an even-C-number long-chain fat, CO, during growth in rats.

The rates of utilization and oxidation of glutamine and glucose by oesophageal and duodenal tissues have been investigated in both rats and human subjects. In the rat, glutamine utilization by oesophageal tissue was 2–3-fold lower than that in the duodenum, and this substrate contributed less than 10 % to the total oxidative metabolism of the tissue, even when glutamine was the only substrate provided. In contrast, rat duodenal tissue derived about 34 % of the total CO2 production from glutamine-C, and this contribution was not suppressed by the addition of either glucose or a mixture of the other substrates. Rates of glucose utilization and oxidation by the duodenum were lower than those for glutamine, and were significantly (P<0·001) suppressed by addition of glutamine. In both oesophageal and duodenal tissues, less than 10 % of the glutamine-C utilized was fully oxidized, approximately 60–70 % was converted to glutamate, and 30–40 % to alanine. Results obtained using human biopsy tissue samples were similar to those observed in the rat. Glutamine oxidation contributed 34 (sd 4) % of the total CO2 production by the duodenal tissue, but only 8 (sd 4) % to oesophageal tissue oxidation. The findings suggest that glutamine is not an important or preferred fuel for oesophageal tissue, whereas it is for duodenal tissue. Thus, these tissues can be expected to respond differently to glutamine administration.

1. The compositions of the lipids in the atheromatous lesions of rabbits have been studied in an experiment in which two groups of rabbits (twelve/group) were given different atherogenic diets for a period of 38 weeks. One group of rabbits was given a diet in which 35% of the total calories was derived from butterfat and the other group was given a diet in which 48% of the total calories was derived from starch.

2. At the end of the feeding period the rabbits were killed and the atheromatous plaques were dissected out from the aortic intima of each rabbit. The lipid compositions of the aortic lesions were determined and the results compared with the compositions of the plasma lipids.

3. In the lipids of the aortic lesions in the rabbits given the high-butterfat diet, the proportions of cholesterol and cholesterol esters were higher and the proportion of triglycerides was lower than in the lipids of the aortic lesions in the rabbits given the high-starch diet. Irrespective of dietary treatment, free cholesterol constituted a higher proportion of the lesion lipids than it did of the plasma lipids.

4. In the rabbits on either dietary treatment, the lesion cholesterol esters contained higher concentrations of oleic acid and lower concentrations of linoleic acid than did the plasma cholesterol esters. In the lesion phospholipids there were higher concentrations of palmitic, palmitoleic, stearic and oleic acids and lower concentrations of linoleic and arachidonic acids than in the plasma phospholipids.

5. In both groups of rabbits the phospholipids of the aortic lesions contained higher proportions of cephalin and sphingomyelin and lower proportions of lecithin than did the plasma phospholipids.

6. The results of this investigation are discussed in relation to the possible origins of the lipids in the aortic lesions of the experimental rabbits.