| 1. |
- Caesar, R, et al.
(författare)
-
Effects of gut microbiota on obesity and atherosclerosis via modulation of inflammation and lipid metabolism.
- 2010
-
Ingår i: Journal of internal medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 268:4, s. 320-8
-
Tidskriftsartikel (refereegranskat)abstract
- Recent studies have revealed a close relationship between inflammatory and metabolic pathways, and inflammation is now recognized to have a major role in obesity and metabolic diseases such as insulin resistance and atherosclerosis. The human body is home to a large number of distinct microbial communities, with the densest population in the distal gut (the gut microbiota). Bacteria have long been known to activate inflammatory pathways, and recent data demonstrate that the gut microbiota may affect lipid metabolism and function as an environmental factor that influences the development of obesity and related diseases. Here, we review how the gut microbiota may affect metabolic diseases by activating the innate immune system.
|
|
| 2. |
- Fåk, Frida, et al.
(författare)
-
Age-related Effects of the Probiotic Bacterium Lactobacillus plantarum 299v on Gastrointestinal Function in Suckling Rats
- 2008
-
Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 53:664-671, s. 664-671
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of a probiotic bacterium on gut function was studied in neonatal animals by using a model with suckling rats. Lactobacillus plantarum 299v (Lp299v) or saline (controls) was fed (3.0 x 10(6) CFU/g b.wt per day) for one week to rats aged either 3, 7 or 14 days, after which bacterial colonization, gut growth, and functional parameters were analyzed. In rats fed with Lp299v from 3 to 10 days of age, an increase in ceacal lactobacilli was correlated with reduced intestinal macromolecular permeability and increased mucosal protein compared to age-matched controls. Pups treated from 7 to 14 days of age showed a decrease in pancreas weight and protein content, whereas pups treated from 14 to 21 days of age showed little effect of the Lp299v treatment. The results indicated that the bacterial exposure affected the gut function, where the effects were age-related and the youngest rats appeared most sensitive.
|
|
| 3. |
- Fåk, Frida, et al.
(författare)
-
Effects of a high-fat diet during pregnancy and lactation are modulated by E. coli in rat offspring
- 2012
-
Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 1476-5497 .- 0307-0565. ; 36:5, s. 744-751
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Microbial manipulations in early life can affect gut development and inflammatory status of the neonate. The maternal diet during pregnancy and lactation also influences the health of the offspring, but the impact of maternal high-fat (HF) feeding along with modulations of the gut microbiota on body weight, fat deposition and gut function in the offspring has been poorly studied. Methods: Rat dams were given access to either an HF or a standard low-fat diet during the last 2 weeks of pregnancy and during lactation and effects on body weight and gastrointestinal function were investigated in the 14-day-old offspring. To elucidate whether bacterial administration to the dam could modulate any effects of the diets in the rat pups, another group of dams were given Escherichia coli in their drinking water. Results: Maternal HF feeding resulted in increased body and fat pad weights in the offspring, along with increased levels of the acute-phase protein, haptoglobin and decreased protein content and disaccharidase activities in the small intestine. The addition of E. coli further accentuated these responses in the young rats, which, in addition to higher body weights and increased fat deposition, also showed an increased intestinal permeability and elevated levels of haptoglobin. Conclusions: The present study demonstrates for the first time how bacterial administration to the maternal diet during the neonatal period can affect body weight and fat deposition in the offspring. The results point to a mechanistic link between the gut microbiota, increased intestinal permeability and metabolic endotoxemia, which appear to have led to increased adiposity in the young rats. International Journal of Obesity (2012) 36, 744-751; doi:10.1038/ijo.2011.118; published online 5 July 2011
|
|
| 4. |
- Fåk, Frida, et al.
(författare)
-
Gastric ghrelin cell development is hampered and plasma ghrelin is reduced by delayed weaning in rats
- 2007
-
Ingår i: Journal of Endocrinology. - : Bioscientifica. - 1479-6805 .- 0022-0795. ; 192:2, s. 345-352
-
Tidskriftsartikel (refereegranskat)abstract
- The duration of breastfeeding has attracted much interest, as a prolonged period of breastfeeding has been shown to reduce the risk of developing obesity. The mechanism behind the reduced risk is, however, poorly understood. The novel hormone ghrelin augments appetite, promotes body. weight increase and increases adiposity. The majority of circulating ghrelin emanates from endocrine cells in the oxyntic mucosa of the stomach. In newborn humans and rodents, the number of ghrelin cells is low after birth until weaning, when the cell population is greatly expanded. To date, information about the influence of weaning perturbations on ghrelin cell development is scarce. Therefore, we studied the effect of delayed weaning on gastric ghrelin expression and plasma ghrelin concentration. To this end, special food separator cages were used to prevent the pups from eating solid food, forcing them to drink milk up to 21 days of age. Gastric ghrelin expression was examined by immunocytochemistry and in situ hybridisation, and plasma concentrations were assessed by RIA. Our data showed that gastric ghrelin expression and plasma ghrelin concentration are maintained at a lower level by delayed weaning. We also found that the relation between gastric ghrelin expression and body weight was altered by delayed weaning. Thus, control rats displayed a positive correlation between ghrelin expression and body weight, while no such correlation was evident in animals with delayed weaning. We conclude that delayed weaning exerts a negative influence on ghrelin expression, and that the onset of solid food intake may trigger normal ghrelin expression. Therefore, we suggest that ghrelin may constitute a hormonal link between the duration of breastfeeding and body weight development.
|
|
| 5. |
- Fåk, Frida
(författare)
-
Impact of the gut microflora on the digestive system in the suckling rat
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The postnatal development of the gastrointestinal (GI) system in mammals is genetically programmed, but is, to an unknown extent, regulated by external factors such as the diet and the gut microflora. These factors can influence the growth of the GI tract, the age-related pattern of appearance of digestive enzymes and the decreased intestinal macromolecular permeability at gut closure, normally timed with weaning in young rodents. The main focus of this doctoral thesis was to elucidate the effect of the colonizing gut microflora as well as to clarify the impact of the maternal microflora on the GI development in rat pups using pro-, pre- and antibiotic manipulations. The suckling rat model was chosen, because the rat is born immature enabling manipulations during its GI development. A probiotic bacterium, Lactobacillus plantarum 299v (Lp299v), having significant health effects in humans and animals and E. coli (CCUG 29300T), an opportunistic bacterium of the family Enterobacteriaceae, as well as broad spectrum antibiotics or a prebiotic inulin preparation, Synergy1, were administered, either directly by gavage to rat pups at various ages during the suckling period, or via the rat dam by administering bacteria or antibiotics in the drinking water. Taken together the results showed that manipulating the gut microflora, either directly or via the mother, affected the growth and function of the GI tract and its associated organs in suckling rats. The effect of Lp299v was age-dependent, where pups colonized early after birth or being offspring born from dams consuming the bacterium showed the greatest impact on the gut function. An altered maternal bacterial flora, induced by antibiotic treatment and E. coli exposure of dams, transfers to the offspring with increased cecal densities of Enterobacteriaceae in the rat pups, which affected the GI development. Moreover, the pups of dams treated with antibiotics showed a delayed stomach development, while the pups of E. coli dams showed an increased growth of the GI system. Increased blood levels of haptoglobin, indicating inflammation, were observed in both groups of pups, which was not seen in the Lp299v exposed pups. Thus, the effects on the GI system are not likely merely mediated by inflammation. Stimulation of the endogenous microflora, by feeding a fiber preparation, enhanced intestinal growth and function in suckling rats. Abstract _________________________________________________________________________ The results obtained in this thesis broaden the knowledge of the impact of specific bacterial groups for growth and function of the digestive system and can hopefully be applied for the care of neonates. The fact that increased numbers of Enterobacteriaceae during the suckling period leads to inflammation might improve our understanding of the “hygiene hypothesis” and the pathogenesis of inflammatory and immune-related bowel diseases in neonates.
|
|
| 6. |
- Fåk, Frida, et al.
(författare)
-
Lactobacillus reuteri Prevents Diet-Induced Obesity, but not Atherosclerosis, in a Strain Dependent Fashion in Apoe-/- Mice
- 2012
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:10
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether the specific strains of Lactobacillus reuteri modulates the metabolic syndrome in Apoe-/- mice. Methods: 8 week-old Apoe-/- mice were subdivided into four groups who received either L. reuteri ATCC PTA 4659 (ATCC), DSM 17938 (DSM), L6798, or no bacterial supplement in the drinking water for 12 weeks. The mice were fed a high-fat Western diet with 0.2% cholesterol and body weights were monitored weekly. At the end of the study, oral glucose and insulin tolerance tests were conducted. In addition, adipose and liver weights were recorded along with analyses of mRNA expression of ileal Angiopoietin-like protein 4 (Angptl4), the macrophage marker F4/80 encoded by the gene Emr1 and liver Acetyl-CoA carboxylase 1 (Acc1), Fatty acid synthase (Fas) and Carnitine palmitoyltransferase 1a (Cpt1a). Atherosclerosis was assessed in the aortic root region of the heart. Results and Conclusions: Mice receiving L. reuteri ATCC gained significantly less body weight than the control mice, whereas the L6798 mice gained significantly more. Adipose and liver weights were also reduced in the ATCC group. Serum insulin levels were lower in the ATCC group, but no significant effects were observed in the glucose or insulin tolerance tests. Lipogenic genes in the liver were not altered by any of the bacterial treatments, however, increased expression of Cpt1a was found in the ATCC group, indicating increased beta-oxidation. Correspondingly, the liver trended towards having lower fat content. There were no effects on inflammatory markers, blood cholesterol or atherosclerosis. In conclusion, the probiotic L. reuteri strain ATCC PTA 4659 partly prevented diet-induced obesity, possibly via a previously unknown mechanism of inducing liver expression of Cpt1a.
|
|
| 7. |
- Fåk, Frida, et al.
(författare)
-
Maternal consumption of Lactobacillus plantarum 299v affects gastrointestinal growth and function in the suckling rat.
- 2008
-
Ingår i: British Journal of Nutrition. - 1475-2662. ; 100:2, s. 332-338
-
Tidskriftsartikel (refereegranskat)abstract
- After birth, the gastrointestinal (GI) tract undergoes vast structural and functional adaptations to be able to digest mother's milk and later, during the weaning period, solid food. Studies on germ-free animals have shown the role of the gut microbiota for stimulating GI maturation, but which groups are involved is unclear. In the present study, we administered the probiotic bacterium, Lactobacillus plantarum 299v (Lp299v), in the drinking water to pregnant and lactating rat dams until their pups had reached an age of 14 d. It was found that Lp299v colonizing the mothers were also able to colonize the pups, which had an impact on their gut growth and function. The small intestine, pancreas and liver weighed more in the 14 d-old pups born from dams exposed to Lp299v than in the control pups from dams given only water. Furthermore, the Lp299v pups showed decreased gut permeability. Despite a heavier spleen in the Lp299v pups, as compared to the control pups, no significant increase in the acute-phase protein, haptoglobin, was found. In conclusion, the results reported here clearly show that manipulating the maternal microflora by exposing expecting mothers to a Gram-positive, probiotic bacterium prior to parturition and during lactation impacts the gut growth and function in the offspring.
|
|
| 8. |
- Fåk, Frida, et al.
(författare)
-
Microbial manipulation of the rat dam changes bacterial colonization and alters properties of the gut in her offspring.
- 2008
-
Ingår i: American Journal of Physiology: Gastrointestinal and Liver Physiology. - : American Physiological Society. - 1522-1547 .- 0193-1857. ; 294, s. 148-154
-
Tidskriftsartikel (refereegranskat)abstract
- The impact of an altered bacterial colonization on gut development has not been thoroughly studied, despite the increased risk of certain diseases with a disturbed microbiota after birth. This study was conducted to determine the effect of microbial manipulation, i.e. antibiotic treatment or Escherichia coli (E. coli) exposure, of the dam on bacterial colonization and gut development in the offspring. Pregnant rats were administered either broad-spectrum antibiotics three days prior to parturition, or live non-pathogenic E. coli CCUG 29300T one week before parturition and up to 14 days of lactation in the drinking water. Caecal bacterial levels, gut growth, intestinal permeability, digestive enzyme levels and intestinal inflammation were studied in two-week old rats. Pups from dams that were antibiotic-treated had higher densities of Enterobacteriaceae which correlated with a decreased stomach growth and function, lower pancreatic protein levels, higher intestinal permeability and increased plasma levels of the acute phase protein, haptoglobin, compared with pups from untreated mothers. Exposure of pregnant/lactating mothers to E. coli CCUG 29300T, also resulting in increased Enterobacteriaceae levels, gave in the offspring similar results on the stomach and an increased small intestinal growth as compared to the control pups. Furthermore, E. coli pups showed increased mucosal disaccharidase activities, increased liver, spleen and adrenal weights, as well as increased plasma concentrations of haptoglobin. These findings indicate that disturbing the normal bacterial colonization after birth, by increasing the densities of caecal Enterobacteriaceae, appear to have lasting effects on the postnatal microflora which affects gut growth and function.
|
|
| 9. |
|
|
| 10. |
- Fåk, Frida, et al.
(författare)
-
Oral microbiota in patients with atherosclerosis
- 2015
-
Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150. ; 243:2, s. 573-578
-
Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Recent evidence suggests that the microbiota may be considered as an environmental factor that contributes to the development of atherosclerosis. Periodontal disease has been associated with cardio- and cerebrovascular events, and inflammation in the periodontium is suggested to increase the systemic inflammatory level of the host, which may in turn influence plaque composition and rupture. We previously showed that bacteria from the oral cavity and the gut could be found in atherosclerotic plaques. Methods: To elucidate whether the oral microbiota composition differed between patients with asymptomatic and symptomatic atherosclerosis we performed pyrosequencing of the oral microbiota of 92 individuals including patients with asymptomatic and symptomatic atherosclerosis and control individuals without carotid plaques or previous stroke or myocardial infarction. Results: The overall microbial structure was similar in controls and atherosclerosis patients, but patients with symptomatic atherosclerosis had higher relative abundance of Anaeroglobus (mean 0.040% (SD 0.049)) than the control group (0.010% (SD 0.028)) (P = 0.03). Using linear regression analysis, we found that Parvimonas associated positively with uCRP and Capnocytophaga, Catonella and Lactobacillus associated with blood lipid markers. In conclusion, abundance of Anaeroglobus in the oral cavity could be associated with symptomatic atherosclerosis. © 2015 Elsevier Ireland Ltd.
|
|
