USE OF A THRAUSTOCHYTRID BIOMASS FOR MAINTAINING GUT BARRIER FUNCTION
20220095648 · 2022-03-31
Assignee
Inventors
Cpc classification
A23V2200/32
HUMAN NECESSITIES
A23K10/30
HUMAN NECESSITIES
International classification
Abstract
A method for maintaining gut barrier function in an individual, comprising administering a Thraustochytrid biomass to an animal in need thereof.
Claims
1. A method for maintaining gut barrier function in an individual, comprising administering a Thraustochytrid biomass for maintaining gut barrier function in an individual to an animal in need thereof.
2. The method according to claim 1, wherein the individual is an individual submitted to stressful or challenging conditions.
3. The method according to claim 1, wherein said Thraustochytrid is of a genus selected from the group consisting of the genera Aplanochytrium, Aurantiochytrium, Botryochytrium, Japonochytrium, Oblongichytrium, Parietichytrium, Phytophthora, Schizochytrium, Sicyoidochytrium, Thraustochytriidae, Thraustochytrium and Ulkenia.
4. The method according to claim 3, wherein said Thraustochytrid is of a genus selected from the group consisting of the genera Aurantiochytrium and Schyzochytrium.
5. The method according to claim 4, wherein said Thraustochytrid is of a species selected from the group consisting of the species Aurantiochytrium mangrovei and Schizochytrium sp.
6. The method according to claim 5, wherein said Thraustochytrid is of a strain selected from the group consisting of the strains Aurantiochytrium mangrovei CCAP 4062/2; Aurantiochytrium mangrovei CCAP 4062/3; Aurantiochytrium mangrovei CCAP 4062/4; Aurantiochytrium mangrovei, CCAP 4062/5; Aurantiochytrium mangrovei CCAP 4062/6; Aurantiochytrium mangrovei CCAP 4062/1; Schizochytrium sp. 4087/3; Schizochytrium sp. CCAP 4087/1; Schizochytrium sp. CCAP 4087/4; and Schizochytrium sp. CCAP 4087/5.
7. The method according to claim 6, wherein said Thraustochytrid is of the strain Aurantiochytrium mangrovei CCAP 4062/5.
8. The method according to claim 1, wherein said Thraustochytrid biomass is in the form of fresh biomass.
9. The method according to claim 1, wherein said Thraustochytrid biomass has been submitted to lysis, transformation by fermentation and/or drying.
10. The method according to claim 1, wherein the Thraustochytrid biomass is a feed ingredient or a feed additive.
11. The method according to claim 1, wherein the Thraustochytrid biomass is added to or incorporated into a compound feed, a food product or food composition.
12. The method according to claim 1, wherein the Thraustochytrid biomass is intended for animal nutrition.
13. The method according to claim 12, wherein the Thraustochytrid biomass is intended for livestock animals feeding.
14. The method according to claim 13, wherein livestock animals are selected from the group consisting of cattle, sheep, pigs, rabbits, poultry and horses.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0047]
[0048]
[0049]
[0050] Top: Length of colon (in cm/kg of body weight (BW)) of 16-day old chickens. ** P<0.05. Bottom: Visual aspect of colon mucosa. A: Control group receiving the basal diet without DSS administration. B: Control group receiving the basal diet with DSS administration. C: Experimental group receiving the diet containing 5% of Aurantiochytrium mangrovei with DSS administration.
[0051]
EXAMPLES
[0052] The present invention is illustrated non-exhaustively by the following examples. These examples are intended for the purpose of illustration only and are not intended to limit the scope of the present invention.
Example 1: Effect of Thraustochytrid Biomass on the TER of Caco-2 Epithelial Cells
[0053] Material and Methods:
[0054] Caco-2 cells were used as a model of intestinal epithelial cells. Cells were routinely grown in culture media (DMEM) supplemented with 10% fetal calf serum and 1% antibiotics (streptomycin penicillin solution). Cells were grown in 75 cm.sup.2 ventilated flasks maintained at 37° C. in a 5% CO.sub.2 incubator. Cells were routinely passaged using trypsin-EDTA solution. For the assay, cells were seeded onto 12-well inserts (Thincert, Greiner, pore size 0.4 μm) at an initial density of 200,000 cells/cm.sup.2 and let to differentiate for 10-14 days post-seeding before being used, with medium changes every two days. Cell differentiation was confirmed by reading the TER, using a Volt/Ohm meter (Millipore), at the beginning of the experiment, when the TER value reached 600 Ohm/cm.sup.2.
[0055] Deoxynivalenol (DON) was used to induce an increased permeability, and various forms of microalgae (Aurantiochytrium mangrovei FCC1325) preparations were tested for their ability to reduce the effect of DON: [0056] fresh microalgae “MF” (i.e. culture from the fermenter without further processing); [0057] lyophilized microalgae “ML” (i.e. microalgae biomass after centrifugation of the culture broth from the fermenter, and lyophilization of the pelleted cells), and [0058] digested lyophilized microalgae “MLD” (i.e. lyophilized microalgae which have been digested in a two-step enzymatic in vitro assay mimicking the pig intestinal tract). The digestion method had two stages: In the first stage, 150 mg of the lyophilized microalgae on a dry matter (DM) basis was weighed into 12 mL tubes containing 7 mL of HCl 0.04 M adjusted to pH 2. A volume of 0.1 mL of pepsin (pig pepsin at 700 FIP-U/g, Merck) dissolved in demineralized water was added to each tube in order to reach a final activity of 500 U/g of tested microalgae on a DM basis. The tubes were incubated with shaking at 15 rotations/min for 2 h at 37° C. At the end of the first incubation period, a second stage mimicking the pancreatic digestion was applied by adding 3 mL of phosphate buffer at pH 7.2 and a pancreatic solution to the digestion tubes. The enzyme solution was prepared (pig pancreatin, grade IV-Sigma n° P-1750, Sigma-Aldrich) at 100 mg/mL in demineralized water, and 0.1 mL of that solution was added to each tube. The digestion mixture was then incubated for an additional 4 h at 37° C. with shaking at 15 rotations/min. After incubation, the microalgae residue remaining after digestion was collected on 50 μm filters, then rinsed first with ethanol for 5-10 min and then acetone for 5-10 min. The digested lyophilized microalgae biomass was finally oven-dried at 35-40° C. (+/−2° C.) for 72 h.
[0059] Both lyophilized (ML) and digested lyophilized (MLD) microalgae powders were resuspended initially at 0.8 mg/ml in buffer (fresh culture medium of the microalgae).
[0060] After differentiation, Caco-2 cells were put in contact, during 48 or 72 h, with or without DON at different concentrations (0, 6.25, 12.5, 25, 50 or 100 μM), and with activated charcoal at 1% (w/v) as positive control, or with or without one of the microalgae preparation type at different concentrations (1, 5, or 20% v:v, final dilution), each added on the apical side. At the end of the incubation time, the TER was measured using a Volt/Ohm meter (Millipore), and results were expressed in percentages of the control put in contact with the same concentration of DON but not with the tested product (microalgae or charcoal). Each condition was tested in triplicates (n=3).
[0061] Results:
[0062] The addition of DON only to the cell medium induced a reduction of the TER (corresponding to an increased permeability), which was even more pronounced as the concentration of DON increased (see “control” condition in
[0063] The half-maximal inhibitory concentration (IC50) is a measure of the potency of a substance in inhibiting a specific biological or biochemical function. This quantitative measure, typically expressed as molar concentration, indicates how much of a particular substance (inhibitor) is needed to inhibit a given biological process by half. The analysis of IC50 at 48 h incubation (Table 1) clearly confirmed the ability of the microalgae to prevent the DON effect on the Caco-2 TER. At 1 and 5%, the fresh and lyophilized microalgae biomass appeared to be the most protective (IC50 values 3-10 times higher, compared to control), while at a concentration of 20%, the digested lyophilized microalgae showed better protection than the fresh and lyophilized biomasses.
TABLE-US-00001 TABLE 1 IC50 at 48 h incubation IC50 (μM) Condition at 48 h Control 11 μM Charcoal >100 μM Fresh microalgae 1% 57 μM Fresh microalgae 5% 51 μM Fresh microalgae 20% >100 μM Lyophilized microalgae ML 1% >100 μM Lyophilized microalgae ML 5% 52 μM Lyophilized microalgae ML 20% >100 μM Digested lyophilized microalgae MLD 1% 100 μM Digested lyophilized microalgae MLD 5% 100 μM Digested lyophilized microalgae MLD 20% 39 μM
[0064] After a 72-h incubation, some of the microalgae showed higher preventive effect than charcoal, and the most efficient prevention was obtained with microalgae at 20% (
Example 2: Effect of Thraustochytrid Biomass on Nutrient Uptake by Caco-2 Epithelial Cells
[0065] Material and Methods:
[0066] In order to test the ability of microalgae to reduce/prevent the effect of DON on nutrient absorption through epithelial cells, Caco-2 cells were exposed to a metabolically active dose of DON, in the absence or presence of Aurantiochytrium mangrovei FCC1325 microalgae (lyophilized microalgae “ML”, or digested lyophilized microalgae “MLD”), at a dose of 1% or 5%. Two main types of nutrients were considered (i.e. glucose and amino acids—more particularly Methionine, Lysine and Threonine), and the following measurements were carried out: [0067] For glucose (D-Glc): passive, active (regulated by the sodium-dependent SGLT-1 transporter) and total (active+passive) absorption [0068] For amino acids (L-Methionine, L-Lysine and L-Threonine): passive, active (regulated by sodium-dependent transport) and total (active+passive) absorption
[0069] Briefly, Caco-2 cells were cultured and seeded onto 12-well inserts, as described in Example 1, and then let to differentiate for 16-21 days post-seeding before being used, with medium changes every two days. When differentiated, Caco-2 cells were incubated or not with DON at 10 μM (apically added), in the absence or presence of 1 or 5% (v:v final dilution, apically added) of microalgae preparation (ML or MLD). Both ML and MLD powders were resuspended initially at 0.8 mg/ml in buffer (fresh culture medium of the microalgae). Caco-2 cells were incubated for 12, 24 or 48 hours before nutrient uptake was measured.
[0070] At the end of the incubation period, inserts were washed twice with PBS++. Inserts were then washed twice with uptake buffer (Ringer Hepes buffer) with or without sodium. Uptake buffer composition was: [0071] Ringer Hepes buffer with sodium (called “+Na+”): 137 mmol/L NaCl, 5.36 mmol/L KCl, 0.4 mmol/L Na.sub.2HPO.sub.4, 0.8 mmol/L MgCl.sub.2, 1.8 mmol/L CaCl.sub.2, 20 mmol/L N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (HEPES), pH being adjusted to pH 7.4 with NaOH; or [0072] Ringer Hepes buffer without sodium (called “—Na+”): 137 mmol/L Choline chloride (instead of sodium chloride), 5.36 mmol/L KCl, 0.4 mmol/L K.sub.2HPO.sub.4 (instead of Na.sub.2HPO.sub.4), 0.8 mmol/L MgCl.sub.2, 1.8 mmol/L CaCl.sub.2, 20 mmol/L N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (HEPES), pH being adjusted to pH 7.4 with KOH.
[0073] After an equilibration period of 15 min at 37° C., uptake assay was initiated by the addition of D-Glc, L-Lysine, L-Methionine or L-Threonine diluted in the appropriate Ringer Hepes buffer (400 μl) and added apically onto Caco-2 inserts (final concentration of 100 μM of D-Glc and 400 μM for amino-acids), the basolateral compartment being filled with 400 μl of buffer. Inserts were kept incubated at 37° C. during the uptake assay. After 15 minutes incubation, 30 μl of media were collected from apical or basolateral compartments and stored at −20° C. until nutrient quantification. Residual concentrations of D-Glc or L-amino acid present in the apical compartments were measured using enzyme-based quantification assay kits (Glucose Colorimetric/Fluorometric Assay Kit, Sigma-Aldrich).
[0074] Uptakes were expressed as: [0075] Total uptake: uptake measured (either measured residual apical concentration or calculated absorbed (intracellular+basolateral) concentration) in Ringer Hepes buffer with Na+corresponding to the activity of sodium-dependent and sodium-independent transporters; [0076] Passive uptake: uptake measured in Ringer Hepes buffer without Na+corresponding to only passive/sodium-independent transporters; [0077] Active uptake: uptake calculated by subtracting passive uptake to total uptake.
[0078] Results:
[0079] D-Glc Uptake after Exposure to DON, in the Absence or Presence of Microalgae
[0080] 12 h Incubation
[0081] At 12 h incubation (see Table 2), ML and MLD suppressed DON effect on total Glc uptake (ML 5% and MLD 1/5%), passive uptake (ML 5% and MLD 1/5%) and SGLT-1 activity (all ML and MLD).
TABLE-US-00002 TABLE 2 Percentage of inhibition of D-glucose uptake by DON after 12 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake SGLT-1 (+Na) (−Na) mediated Control + DON 9.3 6.4 19.2 ML 1% + DON 28.3 37.8 −29.4 ML 5% + DON −24.1 −23.0 −29.5 MLD 1% + DON −5.7 4.4 −60.1 MLD 5% + DON −8.1 −9.3 −2.7
[0082] 24 Incubation
[0083] At 24 h incubation, ML and MLD reversed/prevented DON-mediated inhibition of total, passive and active D-Glc uptake (see Table 3).
TABLE-US-00003 TABLE 3 Percentage of inhibition of D-glucose uptake by DON after 24 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake SGLT-1 (+Na) (−Na) mediated Control + DON 29.4 22.2 52.3 ML 1% + DON 5.3 13.9 −36.8 ML 5% + DON −18.9 −10.0 −211.0 MLD 1% + DON 4.7 −8.8 44.5 MLD 5% + DON −5.8 1.0 −46.8
[0084] 48 h Incubation
[0085] At 48 h incubation, similarly as for the 24 h incubation, ML and MLD reversed/prevented DON-mediated inhibition of total, passive and active D-Glc uptake.
TABLE-US-00004 TABLE 4 Percentage of inhibition of D-glucose uptake by DON after 48 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake SGLT-1 (+Na) (−Na) mediated Control + DON 28.8 21.6 51.4 ML 1% + DON 20.3 19.4 24.9 ML 5% + DON −22.6 −19.6 −128.2 MLD 1% + DON −9.6 −14.2 7.4 MLD 5% + DON −9.8 −4.2 −38.4
[0086] L-Amino Acids Uptake after Exposure to DON, in the Absence or Presence of Microalgae
[0087] 12 h Incubation
[0088] ML and MLD did not prevent the effect of DON on total or passive L-Lys absorption but ML 1% and MLD 1% were able to prevent L-Lys active uptake inhibition by DON (Table 5).
TABLE-US-00005 TABLE 5 Percentage of inhibition of L-Lysine uptake by DON after 12 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control −5.2 −6.1 57.5 ML 1% −12.6 −14.5 18.1 ML 5% −7.4 −15.3 68.1 MLD 1% −23.6 −28.1 28.1 MLD 5% −29.5 −44.0 63.7
[0089] Contrarily to L-Lys and L-Thr that were inhibited by DON, L-Met active uptake was stimulated by DON. ML and MLD were able to limit L-Met uptake stimulation by DON (Table 6).
TABLE-US-00006 TABLE 6 Percentage of inhibition of L-Methionine uptake by DON after 12 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −9.6 −2.2 −256.0 ML 1% + DON −5.6 2.2 −129.1 ML 5% + DON −9.6 −8.5 −28.1 MLD 1% + DON −7.2 −0.4 −159.4 MLD 5% + DON −8.8 −15.6 66.9
[0090] ML but not MLD were able to limit L-Thr active uptake inhibition by DON (Table 7).
TABLE-US-00007 TABLE 7 Percentage of inhibition of L-Threonine uptake by DON after 12 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −6.3 −9.5 56.5 ML 1% + DON −18.1 −14.6 −82.6 ML 5% + DON −14.1 −7.6 −255.4 LD 1% + DON −43.0 −97.5 61.5 MLD 5% + DON −74.6 −94.4 14.3
[0091] 24 h Incubation
[0092] Table 8 shows that ML 1% (but not the other forms of microalgae) was able to reverse the effect of DON on active L-Lys uptake.
[0093] Table 9 shows that both ML and MLD prevented DON effects on L-Met active transport.
[0094] Table 10 shows that ML and MLD 5% prevented the inhibition of L-Thr active uptake by DON.
TABLE-US-00008 TABLE 8 Percentage of inhibition of L-Lysine uptake by DON after 24 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −5.2 −10.1 44.2 ML 1% + DON −10.5 −8.1 −38.9 ML 5% + DON −8.2 −18.3 72.9 MLD 1% + DON −19.5 −27.6 53.5 MLD 5% + DON −36.3 −49.1 33.1
TABLE-US-00009 TABLE 9 Percentage of inhibition of L-Methionine uptake by DON after 24 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −12.9 −4.9 −5220.8 ML 1% + DON −9.5 −13.5 28.7 ML 5% + DON −3.5 −1.1 −46.8 MLD 1% + DON −4.2 8.0 −467.3 MLD 5% + DON −17.3 −1.3 −676.6
TABLE-US-00010 TABLE 10 Percentage of inhibition of L-Threonine uptake by DON after 24 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −6.3 −9.5 56.5 ML 1% + DON −18.1 −14.6 82.6 ML 5% + DON −14.1 −7.6 −255.4 MLD 1% + DON −43.0 −97.5 61.5 MLD 5% + DON −74.6 −94.4 14.3
[0095] 48 h Incubation
[0096] At 48 h incubation, DON stimulated active L-Lys uptake. This effect was prevented by ML but not by MLD (Table 11). At 48 h incubation, DON stimulated active L-Met uptake. This effect was prevented by ML and MLD 5% but not by MLD 1% (Table 12).
TABLE-US-00011 TABLE 11 Percentage of inhibition of L-Lysine uptake by DON after 48 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −9.4 −6.6 −102.3 ML 1% + DON −11.1 −15.0 54.6 ML 5% + DON −6.2 −22.4 87.0 MLD 1% + DON −29.2 −25.3 −202.9 MLD 5% + DON −41.9 −38.6 −201.1
TABLE-US-00012 TABLE 12 Percentage of inhibition of L-Methionine uptake by DON after 48 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −4.1 1.8 −102.4 ML 1% + DON −1.4 0.4 −36.1 ML 5% + DON −6.2 −8.1 39.5 MLD 1% + DON −25.2 3.0 −739.2 MLD 5% + DON −9.0 −8.0 −24.0
[0097] Table 13 shows that both ML and MLD prevented partially the inhibition of active L-Thr uptake by DON.
TABLE-US-00013 TABLE 13 Percentage of inhibition of L-Threonine uptake by DON after 48 h treatment of Caco-2 cells with different microalgae preparations in comparison with cells not treated with DON % of inhibition by DON Total uptake Passive uptake Active (+Na) (−Na) transport Control + DON −14.5 −16.9 76.4 ML 1% + DON −6.0 −11.1 39.6 ML 5% + DON −16.0 −27.0 43.4 MLD 1% + DON −46.9 −76.8 42.8 MLD 5% + DON −60.6 −83.3 45.1
CONCLUSION
[0098] The most important uptakes to be considered are total uptake (in order to have a global view of nutrient uptake capacity) and active uptake (in order to evaluate anti-diarrheal nutrient uptake activity). Overall, results are consistent with previously published results obtained with radioactive nutrients and HT-29-D4 cells, confirming that DON at 10 μM alters intestinal nutrient uptake. These first observations suggested that the lyophilized microalgae with or without pre-digestion is able to partially reverse/prevent DON-mediated impact on total, passive, and active uptake of glucose, Lysine, Threonine, and Methionine.
Example 3: Effect of Thraustochytrid Biomass on Colon Histo-Morphology and Gut Permeability in Broiler Chickens
[0099] Material and Methods: [0100] Experimental animals: Day-of-hatch male Ross 308 broilers were obtained from a local hatchery, placed in floor pens until 6 days of age, and provided heat to maintain an age-appropriate temperature. Chicks were provided ad libitum access to water and the balanced experimental diets meeting the poultry nutrition requirements recommended for Ross 308 broilers during the starter period from 1 to 16 days of age. [0101] Experimental diets: A basal starter diet (CON) in the form of short pellets was formulated based on wheat, corn, and soybean meal (Table 14). The other experimental diets were formulated to contain 5% microalgae Aurantiochytrium mangrovei (MAG-5) or 2% curcumin (CUM-2) by replacing part of the cereal, protein or oil content. The 3 diets were formulated to be isoenergetic and isoprotein (Table 15).
TABLE-US-00014 TABLE 14 Ingredient composition of the experimental diets. INGREDIENTS (G/KG) CON MAG-5 CUM-2 CORN 40.00 40.00 40.00 WHEAT 21.22 21.67 19.19 SOYBEAN MEAL 48 30.10 24.57 30.41 SOY OIL 1.84 1.88 1.62 SOYBEANS 3.00 3.00 3.00 MICROALGAE — 5.00 — CURCUMIN — — 2.00 DICALCIUM PHOSPHATE 1.77 1.69 1.78 CALCIUM CARBONATE 0.50 0.58 0.41 SALT 0.28 0.28 0.28 L-LYSINE HCL 78% 0.23 0.24 0.23 DL-METHIONINE 99 0.32 0.32 0.33 L-THREONINE 98% 0.05 0.07 0.05 SODIUM BICARBONATE 0.10 0.10 0.10 MINERAL PREMIX + ELANCOBAN 0.60 0.60 0.60 TOTAL 100.00 100.00 100.00
TABLE-US-00015 TABLE 15 Nutritional composition of the experimental diets. NUTRIENTS (%) CON MAG-5 CUM-2 AME (KCAL/KG) 2950 2950 2950 CRUDE PROTEIN 20.7 20.5 20.7 CRUDE FAT 4.56 4.93 4.49 CRUDE FIBRE 3.25 3.18 3.47 DIGESTIBLE LYSINE 1.08 1.08 1.08 DIGESTIBLE MET + CYS 0.90 0.90 0.90 DIGESTIBLE THREONINE 0.68 0.68 0.68 DIGESTIBLE TRYPTOPHANE 0.23 0.22 0.23 DIGESTIBLE ARGININE 1.22 1.23 1.22 DIGESTIBLE VALINE 0.82 0.81 0.82 DIGESTIBLE ISOLEUCINE 0.78 0.75 0.78 DIGESTIBLE LEUCINE 1.50 1.45 1.50 TOTAL CALCIUM 0.89 0.89 0.89 TOTAL PHOSPHORUS 0.69 0.77 0.69 AVAILABLE PHOSPHORE 0.40 0.40 0.40 SODIUM 1.5 1.5 1.5 [0102] Dextran Sulfate Sodium (DSS) administration: DSS was used to increase intestinal permeability in broilers, by inducing epithelium damage. DSS (MW 40 kDa, Alfa Aesar, Ward Hill, Mass.) was administered from day 10 to 15 at a concentration of 0.75% (wt/vol) in drinking water. At the end of day 15, all groups were provided fresh water without DSS until final collection of samples at day 16. The DSS solution was prepared daily in fresh water and distributed through individual bottles of water directly connected to the drinking system of each cage. Each bottle was weighted before and after filling with the new DSS solution in order to measure the daily consumption of DSS par cage. Control animals received normal drinking water ad libitum from day 1 to day 16. [0103] Experimental design and measurements of colon length and gut permeability: At 6 days of age, a total of 144 broiler chicks were randomly divided into 4 groups of 12 cages (3 chicks/cage): 1 control group given the control starter diet, and 3 groups receiving DSS and fed on each of the 3 experimental diets (control starter diet, microalgae diet, and curcumin diet—see Table 14). At day 16 (5 d of DSS), chickens were dosed with 2 mL of FITC-dextran (MW 4000; Sigma Aldrich Co., St. Louis, Mo.) by oral gavage at 8 mg/kg in water to detect enteric leakage. One hour after oral gavage, 24 birds from each condition (2 birds/cage) were humanely killed by CO.sub.2 inhalation and bled for plasma collection. Blood was kept on ice in EDTA tubes after sampling, and centrifuged (2000×g for 15 min) to separate plasma. Fluorescence levels of diluted plasma (1:4 in saline solution 0.9% NaCl) were measured at an excitation wavelength of 485 nm and emission wavelength of 528 nm (BIOTEK synergie H1), and FITC-dextran concentration per mL of plasma was calculated based on a standard curve. [0104] At the time of euthanisa, the colon was collected for morphometry. Briefly, the digestive tract of each bird from the proximal esophagus to the cloaca was carefully removed from the body cavity. The colon (from the ileocecal junction to the cloaca) was then excised and its length was measured.
[0105] Results: [0106] Digestive tract measurement (colon length): the length of the colon was measured directly after euthanasia at 16 days of age, and reported of individual body weight. These results, as well as visual observation of the colon mucosa, are presented in